Reorganized slides.
--- a/day1/session3.tex Fri Nov 06 17:56:22 2009 +0530
+++ b/day1/session3.tex Fri Nov 06 18:33:08 2009 +0530
@@ -78,6 +78,7 @@
\author[FOSSEE] {FOSSEE}
\institute[IIT Bombay] {Department of Aerospace Engineering\\IIT Bombay}
+
\date[] {7 November, 2009\\Day 1, Session 3}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@@ -126,67 +127,88 @@
%% % You might wish to add the option [pausesections]
%% \end{frame}
+\section{Computing mean}
+\begin{frame}
+ \frametitle{Value of acceleration due to gravity?}
+ \begin{itemize}
+ \item We already have pendulum.txt
+ \item We know that $ T = 2\pi \sqrt{\frac{L}{g}} $
+ \item So $ g = \frac{4 \pi^2 L}{T^2} $
+ \item Calculate ``g'' - acceleration due to gravity for each pair of L and T
+ \item Hence calculate mean ``g''
+ \end{itemize}
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{Acceleration due to gravity - ``g''\ldots}
+ \begin{lstlisting}
+In []: G = []
+In []: for line in open('pendulum.txt'):
+ .... points = line.split()
+ .... l = float(points[0])
+ .... t = float(points[1])
+ .... g = 4 * pi * pi * l / t * t
+ .... G.append(g)
+ \end{lstlisting}
+\end{frame}
+
+\begin{frame}
+ \frametitle{Computing mean ``g''}
+ \begin{block}{Exercise}
+ Obtain the mean of ``g''
+ \end{block}
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{Mean ``g''}
+ \begin{lstlisting}
+total = 0
+for g in G:
+ total += g
+
+mean_g = total / len(g)
+print "Mean: ", mean_g
+ \end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{Mean ``g''}
+ \begin{lstlisting}
+mean_g = sum(G) / len(G)
+print "Mean: ", mean_g
+ \end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{Mean ``g''}
+ \begin{lstlisting}
+mean_g = mean(G)
+print "Mean: ", mean_g
+ \end{lstlisting}
+ \inctime{10}
+\end{frame}
+
\section{Processing voluminous data}
\begin{frame}
\frametitle{More on data processing}
\begin{block}{}
- We have a huge--1m records--data file.\\How do we do \emph{efficient} statistical computations, that is find mean, median, mode, standard deveiation etc; draw pie charts?
+ We have a huge data file--180,000 records.\\How do we do \emph{efficient} statistical computations, i.e. find mean, median, standard deviation etc; draw pie charts?
\end{block}
\end{frame}
-
-\begin{frame}
- \frametitle{Statistical Analysis: Problem statement}
- Read the data supplied in \emph{sslc1.txt} and carry out the following:
- \begin{enumerate}
- \item Draw a pie chart representing the proportion of students who scored more than 90\% in each region in Science.
- \item Draw a pie chart representing the proportion of students who scored more than 90\% in each subject across regions.
- \item Print mean, median, mode and standard deviation of math scores for all regions combined.
- \end{enumerate}
-\end{frame}
-
-\begin{frame}
- \frametitle{Problem statement: explanation}
- \emphbar{Draw a pie chart representing the proportion of students who scored more than 90\% in each region in Science.}
- \begin{enumerate}
- \item Complete(100\%) data - Number of students who scored more than 90\% in Science
- \item Each slice - Number of students who scored more than 90\% in Science in one region
- \end{enumerate}
-\end{frame}
-
\begin{frame}
- \frametitle{Problem statement: explanation}
- \emphbar{Draw a pie chart representing the proportion of students who scored more than 90\% in each subject across regions.}
- \begin{enumerate}
- \item Complete(100\%) data - Number of students who scored more than 90\% across all regions
- \item Each slice - Number of students who scored more than 90\% in each subject across all regions
- \end{enumerate}
+ \frametitle{Structure of the file}
+ Understanding the structure of sslc1.txt
+ \begin{itemize}
+ \item Each line in the file has a student's details(record)
+ \item Each record consists of fields separated by ';'
+ \end{itemize}
+\emphbar{A;015162;JENIL T P;081;060;77;41;74;333;P;;}
\end{frame}
\begin{frame}
- \frametitle{Statistical Analysis and Parsing \ldots}
- Machinery Required -
- \begin{itemize}
- \item File reading
- \item Parsing
- \item Dictionaries
- \item NumPy arrays
- \item Statistical operations
- \end{itemize}
-\end{frame}
-
-\begin{frame}
- \frametitle{File reading and parsing}
- Understanding the structure of sslc1.txt
- \begin{itemize}
- \item One line in file corresponds to a student's details
- \item aka record
- \item Each record consists of fields separated by ';'
- \end{itemize}
-\end{frame}
-
-\begin{frame}
- \frametitle{File reading and parsing \ldots}
+ \frametitle{Structure of the file \ldots}
+\emphbar{A;015163;JOSEPH RAJ S;083;042;47;AA;72;244;;;}
Each record consists of:
\begin{itemize}
\item Region Code
@@ -195,11 +217,43 @@
\item Marks of 5 subjects: English, Hindi, Maths, Science, Social
\item Total marks
\item Pass/Fail (P/F)
- \item Withdrawn (W)
+ \item Withheld (W)
\end{itemize}
\inctime{5}
\end{frame}
+\begin{frame}
+ \frametitle{Statistical Analysis: Problem statement}
+ 1. Read the data supplied in the file \emph{sslc1.txt} and carry out the following:
+ \begin{itemize}
+ \item[a] Draw a pie chart representing proportion of students who scored more than 90\% in each region in Science.
+ \item[b] Print mean, median and standard deviation of math scores for all regions combined.
+ \end{itemize}
+\end{frame}
+
+\begin{frame}
+ \frametitle{Problem statement: explanation}
+ \emphbar{a. Draw a pie chart representing proportion of students who scored more than 90\% in each region in Science.}
+\begin{columns}
+ \column{5.25\textwidth}
+ \hspace*{.5in}
+\includegraphics[height=2.6in, interpolate=true]{data/science}
+ \column{0.8\textwidth}
+\end{columns}
+\end{frame}
+
+\begin{frame}
+ \frametitle{Machinery Required}
+ \begin{itemize}
+ \item File reading
+ \item Parsing
+ \item Dictionaries
+ \item List enumeration
+ \item Arrays
+ \item Statistical operations
+ \end{itemize}
+\end{frame}
+
\subsection{Data processing}
\begin{frame}[fragile]
\frametitle{File reading and parsing \ldots}
@@ -207,100 +261,71 @@
for record in open('sslc1.txt'):
fields = record.split(';')
\end{lstlisting}
+\begin{block}{}
+\centerline{Recall pendulum example!}
+\end{block}
\end{frame}
-\subsection{Dictionary}
+\subsection{Dictionaries}
\begin{frame}[fragile]
- \frametitle{Dictionary: Introduction}
+ \frametitle{Dictionaries: Introduction}
\begin{itemize}
\item lists index: 0 \ldots n
\item dictionaries index using strings
\end{itemize}
- \begin{block}{Example}
-d = \{ ``Hitchhiker's guide'' : 42,
- ``Terminator'' : ``I'll be back''\}\\
-d[``Terminator''] => ``I'll be back''
- \end{block}
\end{frame}
\begin{frame}[fragile]
- \frametitle{Dictionary: Introduction}
+ \frametitle{Dictionaries \ldots}
\begin{lstlisting}
-In [1]: d = {"Hitchhiker's guide" : 42,
- "Terminator" : "I'll be back"}
+In []: d = {"jpg" : "image file",
+ "txt" : "text file",
+ "py" : "python code"}
-In [2]: d["Hitchhiker's guide"]
-Out[2]: 42
-
-In [3]: "Hitchhiker's guide" in d
-Out[3]: True
-
-In [4]: "Guido" in d
-Out[4]: False
+In []: d["txt"]
+Out[]: 'text file'
\end{lstlisting}
\end{frame}
\begin{frame}[fragile]
- \frametitle{Dictionary: Introduction}
+ \frametitle{Dictionaries \ldots}
\begin{lstlisting}
-In [5]: d.keys()
-Out[5]: ['Terminator', "Hitchhiker's
- guide"]
+In []: "py" in d
+Out[]: True
-In [6]: d.values()
-Out[6]: ["I'll be back", 42]
+In []: "cpp" in d
+Out[]: False
\end{lstlisting}
\end{frame}
\begin{frame}[fragile]
- \frametitle{Back to lists: Iterating}
- \begin{itemize}
- \item Python's \kwrd{for} loop iterates through list items
- \item In other languages (C/C++) we run through indices and pick items from the array using these indices
- \item In Python, while iterating through list items current position is not available
- \end{itemize}
- \begin{block}{Iterating through indices}
- What if we want the index of an item of a list?
- \end{block}
+ \frametitle{Dictionaries \ldots}
+ \begin{lstlisting}
+In []: d.keys()
+Out[]: ['py', 'txt', 'jpg']
+In []: d.values()
+Out[]: ['python code', 'text file',
+ 'image file']
+ \end{lstlisting}
+ \inctime{10}
\end{frame}
\begin{frame}[fragile]
- \frametitle{enumerate: Iterating through list indices}
- \begin{lstlisting}
-In [1]: names = ["Guido","Alex", "Tim"]
-
-In [2]: for i, name in enumerate(names):
- ...: print i, name
- ...:
-0 Guido
-1 Alex
-2 Tim
- \end{lstlisting}
- \inctime{5}
-\end{frame}
-
-\begin{frame}[fragile]
- \frametitle{Continuing with our Dictionary}
+ \frametitle{Getting back to the problem}
Let our dictionary be:
\begin{lstlisting}
-science = {} # is an empty dictionary
+science = {}
\end{lstlisting}
-\end{frame}
-
-\begin{frame}[fragile]
- \frametitle{Dictionary - Building parsed data}
- \begin{itemize}
- \item \emph{Keys} of \emph{science} will be region codes
- \item Value of a \emph{science} will be the number students who scored more than 90\% in that region
+\begin{itemize}
+ \item Keys will be region codes
+ \item Values will be the number students who scored more than 90\% in that region
\end{itemize}
\end{frame}
\begin{frame}[fragile]
\frametitle{Building parsed data \ldots}
\begin{lstlisting}
-from pylab import pie
-
science = {}
for record in open('sslc1.txt'):
@@ -317,9 +342,9 @@
if region_code not in science:
science[region_code] = 0
-score_str = fields[4].strip()
+score_str = fields[6].strip()
-score = int(score_str) if
+score = int(score_str) if \
score_str != 'AA' else 0
if score > 90:
@@ -327,17 +352,25 @@
\end{lstlisting}
\end{frame}
+\begin{frame}[fragile]
+ \frametitle{Building parsed data \ldots}
+ \begin{lstlisting}
+print science
+print science.keys()
+print science.values()
+ \end{lstlisting}
+\end{frame}
+
\subsection{Visualizing data}
\begin{frame}[fragile]
- \frametitle{Pie charts}
+ \frametitle{Pie chart}
\small
\begin{lstlisting}
-figure(1)
pie(science.values(),
- labels=science.keys())
+ labels = science.keys())
title('Students scoring 90% and above
in science by region')
-savefig('/tmp/science.png')
+savefig('science.png')
\end{lstlisting}
\begin{columns}
\column{5.25\textwidth}
@@ -345,148 +378,65 @@
\includegraphics[height=2in, interpolate=true]{data/science}
\column{0.8\textwidth}
\end{columns}
- \inctime{5}
+ \inctime{10}
+\end{frame}
+
+\begin{frame}
+ \frametitle{Problem statement}
+ \emphbar{b. Print mean, median and standard deviation of math scores for all regions combined.}
\end{frame}
\begin{frame}[fragile]
- \frametitle{Building data for all subjects \ldots}
+ \frametitle{Building data for statistics}
\begin{lstlisting}
-from pylab import pie
-from scipy import mean, median, std
-from scipy import stats
+math_scores = []
-scores = [[], [], [], [], []]
-ninety_percents = [{}, {}, {}, {}, {}]
- \end{lstlisting}
-\end{frame}
-
-\begin{frame}[fragile]
- \frametitle{Building data for all subjects \ldots}
- \begin{lstlisting}
for record in open('sslc1.txt'):
record = record.strip()
fields = record.split(';')
- region_code = fields[0].strip()
- \end{lstlisting}
-\end{frame}
-
-\begin{frame}[fragile]
- \frametitle{Building data for all subjects \ldots}
- \small
- \begin{lstlisting}
-for i, field in enumerate(fields[3:8]):
- if region_code not in ninety_percents[i]:
- ninety_percents[i][region_code] = 0
-
- score_str = field.strip()
- score = int(score_str) if
+ score_str = fields[5].strip()
+ score = int(score_str) if \
score_str != 'AA' else 0
- scores[i].append(score)
-
- if score > 90:
- ninety_percents[i][region_code] += 1
- \end{lstlisting}
-\end{frame}
-
-\begin{frame}[fragile]
- \frametitle{Consolidating data}
- \begin{lstlisting}
-subj_total = []
-for subject in ninety_percents:
- subj_total.append(sum(
- subject.values()))
+ math_scores.append(score)
\end{lstlisting}
\end{frame}
-\begin{frame}[fragile]
- \frametitle{Pie charts}
- \begin{lstlisting}
-figure(2)
-pie(subj_total, labels=['English',
- 'Hindi', 'Maths', 'Science',
- 'Social'])
-title('Students scoring more than
- 90% by subject(All regions
- combined).')
-savefig('/tmp/all_regions.png')
- \end{lstlisting}
-\end{frame}
-
-\begin{frame}[fragile]
- \frametitle{Pie charts}
- \includegraphics[height=3in, interpolate=true]{data/all_regions}
-\end{frame}
-
\subsection{Obtaining statistics}
\begin{frame}[fragile]
\frametitle{Obtaining statistics}
- \begin{block}{Statistics: Mean}
+ \begin{block}{Exercise}
Obtain the mean of Math scores
\end{block}
\end{frame}
\begin{frame}[fragile]
- \frametitle{Obtaining statistics: Solution}
- \begin{block}{Statistics: Mean}
- Obtain the mean of Math scores
- \end{block}
- \begin{lstlisting}
-math_scores = scores[2]
-total = 0
-for i, score in enumerate(math_scores):
- total += score
-
-mean = total / (i + 1)
-print "Mean: ", mean
- \end{lstlisting}
-\end{frame}
-
-\begin{frame}[fragile]
- \frametitle{Obtaining statistics: Another solution}
- \begin{block}{Statistics: Mean}
- Obtain the mean of Math scores
- \end{block}
- \begin{lstlisting}
-math_scores = scores[2]
-mean = sum(math_scores) /
- len(math_scores)
- \end{lstlisting}
-\end{frame}
-
-\begin{frame}[fragile]
-\frametitle{NumPy arrays}
- \begin{itemize}
- \item NumPy provides arrays
- \item arrays are very efficient and powerful
- \item Very easy to perform element-wise operations - \typ{+, -, *, /, \%}
- \begin{lstlisting}
-In [1]: a = array([1, 2, 3])
-In [2]: b = array([4, 5, 6])
-
-In [3]: a + b
-Out[3]: array([5, 7, 9])
- \end{lstlisting}
- \item Very easy to compute statistics
- \end{itemize}
-\end{frame}
-
-\begin{frame}[fragile]
\frametitle{Obtaining statistics}
\begin{lstlisting}
-math_scores = array(scores[2])
-
print "Mean: ", mean(math_scores)
print "Median: ", median(math_scores)
-print "Mode: ", stats.mode(math_scores)
-
print "Standard Deviation: ",
std(math_scores)
\end{lstlisting}
- \inctime{15}
+ \inctime{10}
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{Obtaining statistics: efficiently!}
+ \begin{lstlisting}
+math_array = array(math_scores)
+
+print "Mean: ", mean(math_array)
+
+print "Median: ", median(math_array)
+
+print "Standard Deviation: ",
+ std(math_array)
+ \end{lstlisting}
+ \inctime{5}
\end{frame}
\begin{frame}[fragile]
@@ -494,37 +444,9 @@
\begin{itemize}
\item Dictionaries for storing data
\item Facilities for drawing pie charts
- \item NumPy arrays for efficient array manipulations
- \item Functions for statistical computations - mean, median, mode, standard deviation
+ \item Efficient array manipulations
+ \item Functions for statistical computations - mean, median, standard deviation
\end{itemize}
\end{frame}
-\section{Least square fit}
-\begin{frame}
-\frametitle{L vs $T^2$ \ldots}
-Let's go back to the L vs $T^2$ plot
-\begin{itemize}
-\item We first look at obtaining $T^2$ from T
-\item Then, we look at plotting a Least Squares fit
-\end{itemize}
-\end{frame}
-
-\begin{frame}[fragile]
-\frametitle{Dealing with data whole-sale}
-\begin{lstlisting}
-In []: for t in T:
- ....: TSq.append(t*t)
-\end{lstlisting}
-\begin{itemize}
-\item This is not very efficient
-\item We are squaring element after element
-\item We use arrays to make this efficient
-\end{itemize}
-\begin{lstlisting}
-In []: L = array(L)
-In []: T = array(T)
-In []: TSq = T*T
-\end{lstlisting}
-\end{frame}
-
\end{document}
--- a/day2/session1.tex Fri Nov 06 17:56:22 2009 +0530
+++ b/day2/session1.tex Fri Nov 06 18:33:08 2009 +0530
@@ -1,8 +1,8 @@
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%Tutorial slides on Python.
%
-% Author: Prabhu Ramachandran <prabhu at aero.iitb.ac.in>
-% Copyright (c) 2005-2009, Prabhu Ramachandran
+% Author: FOSSEE
+% Copyright (c) 2009, FOSSEE, IIT Bombay
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\documentclass[14pt,compress]{beamer}
@@ -78,7 +78,7 @@
\author[FOSSEE Team] {The FOSSEE Group}
\institute[IIT Bombay] {Department of Aerospace Engineering\\IIT Bombay}
-\date[] {1, November 2009\\Day 2, Session 1}
+\date[] {8 November, 2009\\Day 2, Session 1}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%\pgfdeclareimage[height=0.75cm]{iitmlogo}{iitmlogo}
@@ -140,13 +140,13 @@
\begin{itemize}
\item \kwrd{int}\\ \kwrd{int} = whole number, no matter what the size!
\begin{lstlisting}
-In [1]: a = 13
+In []: a = 13
-In [2]: b = 99999999999999999999
+In []: b = 99999999999999999999
\end{lstlisting}
\item \kwrd{float}
\begin{lstlisting}
-In [3]: fl = 3.141592
+In []: p = 3.141592
\end{lstlisting}
\end{itemize}
\end{frame}
@@ -154,16 +154,16 @@
\begin{frame}[fragile]
\frametitle{Complex numbers}
\begin{lstlisting}
-In [1]: cplx = 3+4j
+In []: c = 3+4j
-In [2]: abs(cplx)
-Out[2]: 5.0
+In []: abs(c)
+Out[]: 5.0
-In [3]: cplx.imag
-Out[3]: 4.0
+In []: c.imag
+Out[]: 4.0
-In [4]: cplx.real
-Out[4]: 3.0
+In []: c.real
+Out[]: 3.0
\end{lstlisting}
\end{frame}
@@ -171,16 +171,31 @@
\begin{frame}[fragile]
\frametitle{Boolean}
\begin{lstlisting}
-In [1]: t = True
+In []: t = True
+
+In []: f = not t
-In [2]: f = not t
-Out[2]: False
+In []: f or t
+Out[]: True
+
+In []: f and t
+Out[]: False
+ \end{lstlisting}
+ \inctime{5}
+\end{frame}
-In [3]: f or t
-Out[3]: True
+\begin{frame}[fragile]
+ \frametitle{( ) for precedence}
+ \begin{lstlisting}
+In []: a = False
+In []: b = True
+In []: c = True
-In [4]: f and t
-Out[4]: False
+In []: (a and b) or c
+Out[]: True
+
+In []: a and (b or c)
+Out[]: False
\end{lstlisting}
\inctime{5}
\end{frame}
@@ -191,20 +206,20 @@
\frametitle{Strings}
Strings were introduced previously, let us now look at them in a little more detail.
\begin{lstlisting}
-In [1]: w = "hello"
+In []: w = "hello"
-In [2]: print w[0] + w[2] + w[-1]
-Out[2]: hlo
+In []: print w[0] + w[2] + w[-1]
+Out[]: hlo
-In [3]: len(w) # guess what
-Out[3]: 5
+In []: len(w) # guess what
+Out[]: 5
\end{lstlisting}
\end{frame}
\begin{frame}[fragile]
\frametitle{Strings \ldots}
\begin{lstlisting}
-In [1]: w[0] = 'H' # Can't do that!
+In []: w[0] = 'H' # Can't do that!
--------------------------------------------
TypeError Traceback (most recent call last)
@@ -218,19 +233,35 @@
\begin{frame}[fragile]
\frametitle{String methods}
\begin{lstlisting}
-In [1]: a = 'Hello World'
-In [2]: a.startswith('Hell')
-Out[2]: True
+In []: a = 'Hello World'
+In []: a.startswith('Hell')
+Out[]: True
+
+In []: a.endswith('ld')
+Out[]: True
-In [3]: a.endswith('ld')
-Out[3]: True
+In []: a.upper()
+Out[]: 'HELLO WORLD'
+
+In []: a.lower()
+Out[]: 'hello world'
+ \end{lstlisting}
+\end{frame}
-In [4]: a.upper()
-Out[4]: 'HELLO WORLD'
-
-In [5]: a.lower()
-Out[5]: 'hello world'
- \end{lstlisting}
+\begin{frame}
+ \frametitle{A bit about IPython}
+ \begin{itemize}
+ \item IPython provides better help
+ \item object.function?
+ \begin{lstlisting}
+In []: a = 'Hello World'
+In []: a.lower?
+ \end{lstlisting}
+ \item It provides tab completion
+ \begin{lstlisting}
+In []: a.s<Tab>
+ \end{lstlisting}
+ \end{itemize}
\end{frame}
\begin{frame}[fragile]
@@ -240,77 +271,102 @@
\item join() is the opposite of split()
\end{itemize}
\begin{lstlisting}
-In [1]: ''.join(['a', 'b', 'c'])
-Out[1]: 'abc'
+In []: ''.join(['a', 'b', 'c'])
+Out[]: 'abc'
\end{lstlisting}
\end{frame}
\begin{frame}[fragile]
\frametitle{String formatting}
\begin{lstlisting}
-In [1]: x, y = 1, 1.234
+In []: x, y = 1, 1.234
-In [2]: 'x is %s, y is %s' %(x, y)
-Out[2]: 'x is 1, y is 1.234'
+In []: 'x is %s, y is %s' %(x, y)
+Out[]: 'x is 1, y is 1.234'
\end{lstlisting}
+ \begin{itemize}
+ \item \emph{\%d}, \emph{\%f} etc. available
+ \end{itemize}
\emphbar{\url{http://docs.python.org/library/stdtypes.html}}
\inctime{10}
\end{frame}
\section{Operators}
\begin{frame}[fragile]
- \frametitle{Arithematic operators}
+ \frametitle{Arithmetic operators}
\begin{lstlisting}
-In [1]: 1786 % 12
-Out[1]: 10
+In []: 1786 % 12
+Out[]: 10
+
+In []: 45 % 2
+Out[]: 1
-In [2]: 3124 * 126789
-Out[2]: 396088836
+In []: 864675 % 10
+Out[]: 5
-In [3]: a = 3124 * 126789
+In []: 3124 * 126789
+Out[]: 396088836
-In [4]: big = 1234567891234567890 ** 3
+In []: big = 1234567891234567890 ** 3
-In [5]: verybig = big * big * big * big
+In []: verybig = big * big * big * big
\end{lstlisting}
\end{frame}
\begin{frame}[fragile]
- \frametitle{Arithematic operators \ldots}
+ \frametitle{Arithmetic operators}
\begin{lstlisting}
-In [1]: 17/2
-Out[1]: 8
+In []: 17 / 2
+Out[]: 8
+
+In []: 17 / 2.0
+Out[]: 8.5
+
+In []: 17.0 / 2
+Out[]: 8.5
+
+In []: 17.0 / 8.5
+Out[]: 2.0
+ \end{lstlisting}
+\end{frame}
-In [2]: 17/2.0
-Out[2]: 8.5
+\begin{frame}[fragile]
+ \frametitle{Arithmetic operators}
+ \begin{lstlisting}
+In []: a = 7546
-In [3]: 17.0/2
-Out[3]: 8.5
+In []: a += 1
+In []: a
+Out[]: 7547
-In [4]: 17.0/8.5
-Out[4]: 2.0
+In []: a -= 5
+In []: a
+
+In []: a *= 2
+
+In []: a /= 5
\end{lstlisting}
\end{frame}
\begin{frame}[fragile]
\frametitle{String operations}
\begin{lstlisting}
-In [1]: s = 'Hello '
+In []: s = 'Hello '
-In [2]: p = 'World'
+In []: p = 'World'
-In [3]: s + p
-Out[3]: 'Hello World'
+In []: s + p
+Out[]: 'Hello World'
-In [4]: s * 4
-Out[4]: 'Hello Hello Hello Hello'
+In []: s * 4
+Out[]: 'Hello Hello Hello Hello'
\end{lstlisting}
\end{frame}
\begin{frame}[fragile]
\frametitle{String operations \ldots}
\begin{lstlisting}
-In [1]: s * s
+In []: s * s
--------------------------------------------
TypeError Traceback (most recent call last)
@@ -324,35 +380,35 @@
\begin{frame}[fragile]
\frametitle{Relational and logical operators}
\begin{lstlisting}
-In [1]: pos, zer, neg = 1, 0, -1
-In [2]: pos == neg
-Out[2]: False
+In []: p, z, n = 1, 0, -1
+In []: p == n
+Out[]: False
-In [3]: pos >= neg
-Out[3]: True
+In []: p >= n
+Out[]: True
-In [4]: neg < zer < pos
-Out[4]: True
+In []: n < z < p
+Out[]: True
-In [5]: pos + neg != zer
-Out[5]: False
+In []: p + n != z
+Out[]: False
\end{lstlisting}
\end{frame}
\begin{frame}[fragile]
\frametitle{Built-ins}
\begin{lstlisting}
-In [1]: int(17/2.0)
-Out[1]: 8
+In []: int(17 / 2.0)
+Out[]: 8
-In [2]: float(17/2) # Recall
-Out[2]: 8.0
+In []: float(17 / 2) # Recall
+Out[]: 8.0
-In [3]: str(17/2.0)
-Out[3]: '8.5'
+In []: str(17 / 2.0)
+Out[]: '8.5'
-In [4]: round( 7.5 )
-Out[4]: 8.0
+In []: round( 7.5 )
+Out[]: 8.0
\end{lstlisting}
\end{frame}
@@ -362,15 +418,15 @@
\item Case sensitive
\item Dynamically typed $\Rightarrow$ need not specify a type
\begin{lstlisting}
-In [1]: a = 1
-In [2]: a = 1.1
-In [3]: a = "Now I am a string!"
+In []: a = 1
+In []: a = 1.1
+In []: a = "Now I am a string!"
\end{lstlisting}
\item Comments:
\begin{lstlisting}
-In [4]: a = 1 # In-line comments
-In [5]: # A comment line.
-In [6]: a = "# Not a comment!"
+In []: a = 1 # In-line comments
+In []: # A comment line.
+In []: a = "# Not a comment!"
\end{lstlisting}
\end{itemize}
\inctime{15}
@@ -379,14 +435,15 @@
\section{Simple IO}
\begin{frame}[fragile]
\frametitle{Simple IO: Console Input}
+ \small
\begin{itemize}
\item raw\_input() waits for user input.
\begin{lstlisting}
-In [1]: a = raw_input()
+In []: a = raw_input()
5
-In [2]: a = raw_input('prompt > ')
-prompt > 5
+In []: a = raw_input('Enter a value: ')
+Enter a value: 5
\end{lstlisting}
\item Prompt string is optional.
\item All keystrokes are Strings!
@@ -394,11 +451,36 @@
\end{itemize}
\end{frame}
-\begin{frame}{Simple IO: Console output}
+\begin{frame}[fragile]
+ \frametitle{Simple IO: Console output}
\begin{itemize}
\item \texttt{print} is straight forward
- \item Note the distinction between \texttt{print x} and \texttt{print x,}
+ \item Put the following code snippet in a file
\end{itemize}
+ \begin{lstlisting}
+print "Hello"
+print "World"
+
+
+In []: %run -i hello1.py
+Hello
+World
+ \end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{Simple IO: Console output \ldots}
+Put the following code snippet in a file
+ \begin{lstlisting}
+print "Hello",
+print "World"
+
+
+In []: %run -i hello2.py
+Hello World
+ \end{lstlisting}
+
+\emphbar{Note the distinction between \texttt{print x} and \texttt{print x,}}
\end{frame}
\section{Control flow}
@@ -406,8 +488,9 @@
\frametitle{Control flow constructs}
\begin{itemize}
\item \kwrd{if/elif/else}: branching
+ \item \kwrd{C if X else Y}: Ternary conditional operator
\item \kwrd{while}: looping
- \item \kwrd{for}: iterating
+ \item \kwrd{for}: iterating
\item \kwrd{break, continue}: modify loop
\item \kwrd{pass}: syntactic filler
\end{itemize}
@@ -416,101 +499,41 @@
\subsection{Basic Conditional flow}
\begin{frame}[fragile]
\frametitle{\typ{If...elif...else} example}
+ \small
\begin{lstlisting}
-x = int(raw_input("Enter an integer:"))
-if x < 0:
- print 'Be positive!'
-elif x == 0:
- print 'Zero'
-elif x == 1:
- print 'Single'
-else:
- print 'More'
+In []: x = int(raw_input("Enter an integer:"))
+
+In []: if x < 0:
+ ...: print 'Be positive!'
+ ...: elif x == 0:
+ ...: print 'Zero'
+ ...: elif x == 1:
+ ...: print 'Single'
+ ...: else:
+ ...: print 'More'
+ ...:
+ ...:
\end{lstlisting}
\inctime{10}
\end{frame}
-\subsection{Basic Looping}
\begin{frame}[fragile]
- \frametitle{\typ{while}}
-Example: Fibonacci series
- \begin{lstlisting}
-# the sum of two elements
-# defines the next
-a, b = 0, 1
-while b < 10:
- print b,
- a, b = b, a + b
-\end{lstlisting}
-\typ{1 1 2 3 5 8}\\
-\end{frame}
-
-\begin{frame}[fragile]
-\frametitle{\typ{range()}}
-\kwrd{range([start,] stop[, step])}\\
-\begin{itemize}
- \item range() returns a list of integers
- \item The \emph{start} and the \emph{step} arguments are optional
- \item \emph{stop} argument is not included in the list
-\end{itemize}
-\end{frame}
-
-\begin{frame}[fragile]
- \frametitle{\typ{for} \ldots \typ{range()}}
-Example: print squares of first \typ{n} numbers
+ \frametitle{Ternary conditional operator}
\begin{lstlisting}
-In []: for i in range(5):
- ....: print i, i * i
- ....:
- ....:
-0 0
-1 1
-2 4
-3 9
-4 16
-\end{lstlisting}
-\inctime{5}
-\end{frame}
-
-\subsection{Exercises}
-
-\begin{frame}{Problem set 1: Problem 1.1}
- Write a program that displays all three digit numbers that are equal to the sum of the cubes of their digits. That is, print numbers $abc$ that have the property $abc = a^3 + b^3 + c^3$\\
-\vspace*{0.2in}
-\emphbar{These are called $Armstrong$ numbers.}
-\end{frame}
-
-\begin{frame}{Problem 1.2 - Collatz sequence}
-\begin{enumerate}
- \item Start with an arbitrary (positive) integer.
- \item If the number is even, divide by 2; if the number is odd, multiply by 3 and add 1.
- \item Repeat the procedure with the new number.
- \item It appears that for all starting values there is a cycle of 4, 2, 1 at which the procedure loops.
-\end{enumerate}
- Write a program that accepts the starting value and prints out the Collatz sequence.
-\end{frame}
-
-\begin{frame}[fragile]{Problem 1.3}
- Write a program that prints the following pyramid on the screen.
- \begin{lstlisting}
-1
-2 2
-3 3 3
-4 4 4 4
+...
+a = raw_input('Enter number(Q to quit):')
+num = int(a) if a != 'Q' else break
+...
\end{lstlisting}
-The number of lines must be obtained from the user as input.\\
-\pause
-\emphbar{When can your code fail?}
-\inctime{5}
\end{frame}
\begin{frame}[fragile]
\frametitle{What did we learn?}
\begin{itemize}
- \item Basic data types
- \item Operators
- \item Conditional structures
- \item Loops
+ \item Data types: int, float, complex, boolean, string
+ \item Operators: +, -, *, /, \%, **, +=, -=, *=, /=, >, <, <=, >=, ==, !=, a < b < c
+ \item Simple IO: \kwrd{raw\_input} and \kwrd{print}
+ \item Conditional structures: \kwrd{if/elif/else},\\ \kwrd{C if X else Y}
\end{itemize}
\end{frame}
--- a/day2/session2.tex Fri Nov 06 17:56:22 2009 +0530
+++ b/day2/session2.tex Fri Nov 06 18:33:08 2009 +0530
@@ -1,8 +1,8 @@
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%Tutorial slides on Python.
%
-% Author: Prabhu Ramachandran <prabhu at aero.iitb.ac.in>
-% Copyright (c) 2005-2009, Prabhu Ramachandran
+% Author: FOSSEE
+% Copyright (c) 2009, FOSSEE, IIT Bombay
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\documentclass[14pt,compress]{beamer}
@@ -78,7 +78,7 @@
\author[FOSSEE Team] {The FOSSEE Group}
\institute[IIT Bombay] {Department of Aerospace Engineering\\IIT Bombay}
-\date[] {1, November 2009\\Day 2, Session 2}
+\date[] {8 November, 2009\\Day 2, Session 2}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%\pgfdeclareimage[height=0.75cm]{iitmlogo}{iitmlogo}
@@ -123,13 +123,113 @@
% You might wish to add the option [pausesections]
\end{frame}
+\section{Control flow}
+\subsection{Basic Looping}
+\begin{frame}[fragile]
+ \frametitle{\typ{while}}
+Example: Fibonacci series
+ \begin{lstlisting}
+# the sum of two elements
+# defines the next
+In []: a, b = 0, 1
+In []: while b < 10:
+ ...: print b,
+ ...: a, b = b, a + b
+ ...:
+ ...:
+\end{lstlisting}
+\typ{1 1 2 3 5 8}\\
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{\typ{range()}}
+\kwrd{range([start,] stop[, step])}\\
+\begin{itemize}
+ \item range() returns a list of integers
+ \item The \emph{start} and the \emph{step} arguments are optional
+ \item \emph{stop} argument is not included in the list
+\end{itemize}
+\vspace*{.5in}
+\begin{itemize}
+ \item \alert{Anything within \typ{[]} is optional}
+ \begin{itemize}
+ \item Nothing to do with Python.
+ \end{itemize}
+\end{itemize}
+
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{\typ{for} \ldots \typ{range()}}
+Example: print squares of first \typ{n} numbers
+ \begin{lstlisting}
+In []: for i in range(5):
+ ....: print i, i * i
+ ....:
+ ....:
+0 0
+1 1
+2 4
+3 9
+4 16
+\end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{\typ{for} \ldots \typ{range()}}
+Example: print squares of odd numbers from 3 to 9
+ \begin{lstlisting}
+In []: for i in range(3, 10, 2):
+ ....: print i, i * i
+ ....:
+ ....:
+3 9
+5 25
+7 49
+9 81
+\end{lstlisting}
+\inctime{5}
+\end{frame}
+
+\subsection{Exercises}
+
+\begin{frame}{Problem set 1: Problem 1.1}
+ Write a program that displays all three digit numbers that are equal to the sum of the cubes of their digits. That is, print numbers $abc$ that have the property $abc = a^3 + b^3 + c^3$\\
+\vspace*{0.2in}
+\emphbar{These are called $Armstrong$ numbers.}
+\end{frame}
+
+\begin{frame}{Problem 1.2 - Collatz sequence}
+\begin{enumerate}
+ \item Start with an arbitrary (positive) integer.
+ \item If the number is even, divide by 2; if the number is odd, multiply by 3 and add 1.
+ \item Repeat the procedure with the new number.
+ \item It appears that for all starting values there is a cycle of 4, 2, 1 at which the procedure loops.
+\end{enumerate}
+ Write a program that accepts the starting value and prints out the Collatz sequence.
+\end{frame}
+
+\begin{frame}[fragile]{Problem 1.3}
+ Write a program that prints the following pyramid on the screen.
+ \begin{lstlisting}
+1
+2 2
+3 3 3
+4 4 4 4
+ \end{lstlisting}
+The number of lines must be obtained from the user.\\
+\pause
+\emphbar{When can your code fail?}
+\inctime{5}
+\end{frame}
+
\section{Data structures}
\subsection{Lists}
\begin{frame}[fragile]
\frametitle{Lists}
\begin{block}{We already know that}
\begin{lstlisting}
-num = [1, 2, 3, 4, 5, 6, 7, 8]
+num = [1, 2, 3, 4]
\end{lstlisting}
\centerline{is a list}
\end{block}
@@ -138,29 +238,76 @@
\begin{frame}[fragile]
\frametitle{Lists: methods}
\begin{lstlisting}
+In []: num = [1, 2, 3, 4]
+
+In []: num.append([9, 10, 11])
+
+In []: num
+Out[]: [1, 2, 3, 4, [9, 10, 11]]
+ \end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{Lists: methods}
+ \begin{lstlisting}
+In []: num = [1, 2, 3, 4]
+
+In []: num.extend([5, 6, 7])
+In []: num
+Out[]: [1, 2, 3, 4, 5, 6, 7]
+
In []: num.reverse()
In []: num
-Out[]: [8, 7, 6, 5, 4, 3, 2, 1]
+Out[]: [7, 6, 5, 4, 3, 2, 1]
-In []: num.extend([0, -1, -2])
+In []: num.remove(6)
In []: num
-Out[]: [8, 7, 6, 5, 4, 3, 2, 1, 0, -1]
+ \end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{Lists: slicing}
+ \begin{itemize}
+ \item \typ{list[initial:final]}
+ \end{itemize}
+\begin{lstlisting}
+In []: a = [1, 2, 3, 4, 5]
+
+In []: a[1:3]
+Out[]: [2, 3]
+
+In []: a[1:-1]
+Out[]: [2, 3, 4]
-In []: num.remove(0)
-In []: num
-Out[]: [8, 7, 6, 5, 4, 3, 2, 1, -1]
- \end{lstlisting}
+In []: a[:3]
+Out[]: [1, 2, 3]
+\end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{Lists: slicing}
+ \begin{itemize}
+ \item \typ{list[initial:final:step]}
+ \end{itemize}
+\begin{lstlisting}
+In []: a[1:-1:2]
+Out[]: [2, 4]
+
+In []: a[::2]
+Out[]: [1, 3, 5]
+
+In []: a[-1::-1]
+Out[]: [5, 4, 3, 2, 1]
+\end{lstlisting}
\end{frame}
\begin{frame}[fragile]
\frametitle{List containership}
\begin{lstlisting}
-In []: a = 8
-
-In []: a in num
+In []: 4 in num
Out[]: True
-In []: b = 10
+In []: b = 15
In []: b in num
Out[]: False
@@ -174,9 +321,14 @@
\frametitle{Tuples: Immutable lists}
\begin{lstlisting}
In []: t = (1, 2, 3, 4, 5, 6, 7, 8)
+
In []: t[0] + t[3] + t[-1]
Out[]: 13
+
+# Try the following!
+In []: t[4] = 7
\end{lstlisting}
+\pause
\begin{block}{Note:}
\begin{itemize}
\item Tuples are immutable - cannot be changed
@@ -200,7 +352,7 @@
\subsection{Dictionaries}
\begin{frame}[fragile]
- \frametitle{Dictionaries: Recall}
+ \frametitle{Dictionaries: recall}
\begin{lstlisting}
In []: player = {'Mat': 134,'Inn': 233,
'Runs': 10823, 'Avg': 52.53}
@@ -214,6 +366,28 @@
\end{block}
\end{frame}
+\begin{frame}[fragile]
+ \frametitle{Dictionaries: containership}
+ \begin{lstlisting}
+In []: 'Inn' in player
+Out[]: True
+
+In []: 'Econ' in player
+Out[]: False
+ \end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{Dictionaries: methods}
+ \begin{lstlisting}
+In []: player.keys()
+Out[]: ['Runs', 'Inn', 'Avg', 'Mat']
+
+In []: player.values()
+Out[]: [10823, 233, 52.530000000000001, 134]
+ \end{lstlisting}
+\end{frame}
+
\begin{frame} {Problem Set 2.1: Problem 2.1.1}
You are given date strings of the form ``29, Jul 2009'', or ``4 January 2008''. In other words a number, a string and another number, with a comma sometimes separating the items.\\Write a function that takes such a string and returns a tuple (yyyy, mm, dd) where all three elements are ints.
\end{frame}
@@ -228,32 +402,47 @@
\item >, >=, <, <=, in, \ldots
\end{itemize}
\begin{lstlisting}
->>> f10 = set([1,2,3,5,8])
->>> p10 = set([2,3,5,7])
->>> f10|p10
-set([1, 2, 3, 5, 7, 8])
->>> f10&p10
-set([2, 3, 5])
->>> f10-p10
-set([8, 1])
+
+In []: f10 = set([1,2,3,5,8])
+
+In []: p10 = set([2,3,5,7])
+
+In []: f10 | p10
+Out[]: set([1, 2, 3, 5, 7, 8])
\end{lstlisting}
\end{frame}
\begin{frame}[fragile]
- \frametitle{Set}
+ \frametitle{Set \ldots}
\begin{lstlisting}
->>> p10-f10, f10^p10
-set([7]), set([1, 7, 8])
->>> set([2,3]) < p10
-True
->>> set([2,3]) <= p10
-True
->>> 2 in p10
-True
->>> 4 in p10
-False
->>> len(f10)
-5
+In []: f10 & p10
+Out[]: set([2, 3, 5])
+
+In []: f10 - p10
+Out[]: set([1, 8])
+
+In []: p10 - f10, f10 ^ p10
+Out[]: (set([7]), set([1, 7, 8]))
+
+In []: set([2,3]) < p10
+Out[]: True
+\end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{Set \ldots}
+ \begin{lstlisting}
+In []: set([2,3]) <= p10
+Out[]: True
+
+In []: 2 in p10
+Out[]: True
+
+In []: 4 in p10
+Out[]: False
+
+In []: len(f10)
+Out[]: 5
\end{lstlisting}
\end{frame}
@@ -261,7 +450,14 @@
\frametitle{Problem set 2.2}
\begin{description}
\item[2.2.1] Given a dictionary of the names of students and their marks, identify how many duplicate marks are there? and what are these?
- \item[2.2.2] Given a string of the form ``4-7, 9, 12, 15'' find the missing numbers in the given range.
+\end{description}
+\inctime{15}
+\end{frame}
+
+\begin{frame}
+ \frametitle{Problem set 2.2}
+ \begin{description}
+ \item[2.2.2] Given a list of words, find all the anagrams in the list
\end{description}
\inctime{15}
\end{frame}
@@ -294,6 +490,19 @@
\end{frame}
\begin{frame}[fragile]
+ \frametitle {What does this function do?}
+ \begin{lstlisting}
+def what( n ):
+ if n < 0: n = -n
+ while n > 0:
+ if n % 2 == 1:
+ return False
+ n /= 10
+ return True
+ \end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
{What does this function do?}
\begin{lstlisting}
def what( n ):
@@ -304,219 +513,13 @@
\end{lstlisting}
\end{frame}
-\subsection{Default arguments}
-\begin{frame}[fragile]
- \frametitle{Functions: default arguments}
- \small
- \begin{lstlisting}
-def ask_ok(prompt, complaint='Yes or no!'):
- while True:
- ok = raw_input(prompt)
- if ok in ('y', 'ye', 'yes'):
- return True
- if ok in ('n', 'no', 'nop',
- 'nope'):
- return False
- print complaint
-
-ask_ok('?')
-ask_ok('?', '[Y/N]')
- \end{lstlisting}
-\end{frame}
-
-\subsection{Built-in functions}
\begin{frame}
- {Before writing a function}
- \begin{itemize}
- \item Variety of builtin functions are available
- \item \typ{abs, any, all, len, max, min}
- \item \typ{pow, range, sum, type}
- \item Refer here:
- \url{http://docs.python.org/library/functions.html}
- \end{itemize}
- \inctime{10}
-\end{frame}
-
-\subsection{Exercises}
-\begin{frame}{Problem set 3: Problem 3.1}
- Write a function to return the gcd of two numbers.
-\end{frame}
-
-\begin{frame}{Problem 3.2}
-Write a program to print all primitive pythagorean triads (a, b, c) where a, b are in the range 1---100 \\
-A pythagorean triad $(a,b,c)$ has the property $a^2 + b^2 = c^2$.\\By primitive we mean triads that do not `depend' on others. For example, (4,3,5) is a variant of (3,4,5) and hence is not primitive. And (10,24,26) is easily derived from (5,12,13) and is also not primitive.
-\end{frame}
-
-\begin{frame}{Problem 3.3}
- Write a program that generates a list of all four digit numbers that have all their digits even and are perfect squares.\newline\\\emph{For example, the output should include 6400 but not 8100 (one digit is odd) or 4248 (not a perfect square).}
-\inctime{15}
-\end{frame}
-
-\section{Modules}
-\begin{frame}[fragile]
- {Modules}
-\begin{lstlisting}
->>> sqrt(2)
-Traceback (most recent call last):
- File "<stdin>", line 1, in <module>
-NameError: name 'sqrt' is not defined
->>> import math
->>> math.sqrt(2)
-1.4142135623730951
-\end{lstlisting}
-\end{frame}
-
-\begin{frame}[fragile]
- {Modules}
- \begin{itemize}
- \item The \kwrd{import} keyword ``loads'' a module
- \item One can also use:
- \begin{lstlisting}
->>> from math import sqrt
->>> from math import *
- \end{lstlisting}
- \item What is the difference?
- \item \alert{Use the latter only in interactive mode}
- \end{itemize}
- \emphbar{Package hierarchies}
- \begin{lstlisting}
->>> from os.path import exists
- \end{lstlisting}
-\end{frame}
-
-\begin{frame}
- \frametitle{Modules: Standard library}
+ \frametitle{What did we learn?}
\begin{itemize}
- \item Very powerful, ``Batteries included''
- \item Some standard modules:
- \begin{itemize}
- \item Math: \typ{math}, \typ{random}
- \item Internet access: \typ{urllib2}, \typ{smtplib}
- \item System, Command line arguments: \typ{sys}
- \item Operating system interface: \typ{os}
- \item Regular expressions: \typ{re}
- \item Compression: \typ{gzip}, \typ{zipfile}, and \typ{tarfile}
- \item And a whole lot more!
- \end{itemize}
- \item Check out the Python Library reference:
- \url{http://docs.python.org/library/}
- \end{itemize}
-\inctime{5}
-\end{frame}
-
-\section{Coding Style}
-\begin{frame}{Readability and Consistency}
- \begin{itemize}
- \item Readability Counts!\\Code is read more often than its written.
- \item Consistency!
- \item Know when to be inconsistent.
- \end{itemize}
-\end{frame}
-
-\begin{frame}[fragile] \frametitle{A question of good style}
- \begin{lstlisting}
- amount = 12.68
- denom = 0.05
- nCoins = round(amount/denom)
- rAmount = nCoins * denom
- \end{lstlisting}
- \pause
- \begin{block}{Style Rule \#1}
- Naming is 80\% of programming
- \end{block}
-\end{frame}
-
-\begin{frame}[fragile]
- \frametitle{Code Layout}
- \begin{itemize}
- \item Indentation
- \item Tabs or Spaces??
- \item Maximum Line Length
- \item Blank Lines
- \item Encodings
- \end{itemize}
-\end{frame}
-
-\begin{frame}{Whitespaces in Expressions}
- \begin{itemize}
- \item When to use extraneous whitespaces??
- \item When to avoid extra whitespaces??
- \item Use one statement per line
- \end{itemize}
-\end{frame}
-
-\begin{frame}{Comments}
- \begin{itemize}
- \item No comments better than contradicting comments
- \item Block comments
- \item Inline comments
- \end{itemize}
-\end{frame}
-
-\begin{frame}{Docstrings}
- \begin{itemize}
- \item When to write docstrings?
- \item Ending the docstrings
- \item One liner docstrings
- \end{itemize}
-More information at PEP8: http://www.python.org/dev/peps/pep-0008/
-\inctime{5}
-\end{frame}
-
-\section{Objects}
-\begin{frame}{Objects in general}
- \begin{itemize}
- \item What is an Object? (Types and classes)
- \item identity
- \item type
- \item method
- \end{itemize}
-\end{frame}
-
-\begin{frame}{Almost everything is an Object!}
- \begin{itemize}
- \item \typ{list}
- \item \typ{tuple}
- \item \typ{string}
- \item \typ{dictionary}
- \item \typ{function}
- \item Of course, user defined class objects!
- \end{itemize}
-\end {frame}
-
-\begin{frame}{Using Objects}
- \begin{itemize}
- \item Creating Objects: Initialization
- \item Object Manipulation: Object methods and ``.'' operator
+ \item Loops: \kwrd{while}, \kwrd{for}
+ \item Advanced Data structures
+ \item Functions
\end{itemize}
\end{frame}
-\begin{frame}[fragile]
- \frametitle{Objects provide consistency}
- \small
- \begin{lstlisting}
-for element in (1, 2, 3):
- print element
-for key in {'one':1, 'two':2}:
- print key
-for char in "123":
- print char
-for line in open("myfile.txt"):
- print line
-for line in urllib2.urlopen('http://site.com'):
- print line
- \end{lstlisting}
-\inctime{10}
-\end{frame}
-
-\begin{frame}
- \frametitle{What did we learn?}
- \begin{itemize}
- \item Lists, Tuples, Dictionaries, Sets: creation and manipulation
- \item More about functions
- \item Coding style
- \item Objects: creation and manipulation
- \end{itemize}
-\end{frame}
-
-\end{document}
+\end{document}
\ No newline at end of file
--- a/day2/session3.tex Fri Nov 06 17:56:22 2009 +0530
+++ b/day2/session3.tex Fri Nov 06 18:33:08 2009 +0530
@@ -1,48 +1,33 @@
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-% Tutorial slides on Python.
+%Tutorial slides on Python.
%
-% Author: Prabhu Ramachandran <prabhu at aero.iitb.ac.in>
-% Copyright (c) 2005-2009, Prabhu Ramachandran
+% Author: FOSSEE
+% Copyright (c) 2009, FOSSEE, IIT Bombay
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\documentclass[compress,14pt]{beamer}
-% \documentclass[handout]{beamer}
-% \usepackage{pgfpages}
-% \pgfpagesuselayout{4 on 1}[a4paper,border, shrink=5mm,landscape]
-\usepackage{tikz}
-\newcommand{\hyperlinkmovie}{}
-%\usepackage{movie15}
+\documentclass[14pt,compress]{beamer}
+%\documentclass[draft]{beamer}
+%\documentclass[compress,handout]{beamer}
+%\usepackage{pgfpages}
+%\pgfpagesuselayout{2 on 1}[a4paper,border shrink=5mm]
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-% Note that in presentation mode
-% \paperwidth 364.19536pt
-% \paperheight 273.14662pt
-% h/w = 0.888
-
-
+% Modified from: generic-ornate-15min-45min.de.tex
\mode<presentation>
{
\usetheme{Warsaw}
- %\usetheme{Boadilla}
- %\usetheme{default}
\useoutertheme{infolines}
\setbeamercovered{transparent}
}
-% To remove navigation symbols
-\setbeamertemplate{navigation symbols}{}
-
-\usepackage{amsmath}
\usepackage[english]{babel}
\usepackage[latin1]{inputenc}
-\usepackage{times}
+%\usepackage{times}
\usepackage[T1]{fontenc}
% Taken from Fernando's slides.
\usepackage{ae,aecompl}
\usepackage{mathpazo,courier,euler}
\usepackage[scaled=.95]{helvet}
-\usepackage{pgf}
\definecolor{darkgreen}{rgb}{0,0.5,0}
@@ -55,65 +40,50 @@
keywordstyle=\color{blue}\bfseries}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-% My Macros
-\setbeamercolor{postit}{bg=yellow,fg=black}
+% Macros
\setbeamercolor{emphbar}{bg=blue!20, fg=black}
\newcommand{\emphbar}[1]
{\begin{beamercolorbox}[rounded=true]{emphbar}
{#1}
\end{beamercolorbox}
}
-%{\centerline{\fcolorbox{gray!50} {blue!10}{
-%\begin{minipage}{0.9\linewidth}
-% {#1}
-%\end{minipage}
-% }}}
-
-\newcommand{\myemph}[1]{\structure{\emph{#1}}}
-\newcommand{\PythonCode}[1]{\lstinline{#1}}
-
-\newcommand{\tvtk}{\texttt{tvtk}}
-\newcommand{\mlab}{\texttt{mlab}}
-
\newcounter{time}
\setcounter{time}{0}
-\newcommand{\inctime}[1]{\addtocounter{time}{#1}{\vspace*{0.1in}\tiny \thetime\ m}}
+\newcommand{\inctime}[1]{\addtocounter{time}{#1}{\tiny \thetime\ m}}
+
+\newcommand{\typ}[1]{\texttt{#1}}
+
+\newcommand{\kwrd}[1]{ \texttt{\textbf{\color{blue}{#1}}} }
-\newcommand\BackgroundPicture[1]{%
- \setbeamertemplate{background}{%
- \parbox[c][\paperheight]{\paperwidth}{%
- \vfill \hfill
- \hfill \vfill
-}}}
-
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-% Configuring the theme
-%\setbeamercolor{normal text}{fg=white}
-%\setbeamercolor{background canvas}{bg=black}
-
+%%% This is from Fernando's setup.
+% \usepackage{color}
+% \definecolor{orange}{cmyk}{0,0.4,0.8,0.2}
+% % Use and configure listings package for nicely formatted code
+% \usepackage{listings}
+% \lstset{
+% language=Python,
+% basicstyle=\small\ttfamily,
+% commentstyle=\ttfamily\color{blue},
+% stringstyle=\ttfamily\color{orange},
+% showstringspaces=false,
+% breaklines=true,
+% postbreak = \space\dots
+% }
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Title page
-\title[3D Plotting]{3D data Visualization}
+\title[Basic Python]{Python language: Data structures and functions}
-\author[FOSSEE] {FOSSEE}
+\author[FOSSEE Team] {The FOSSEE Group}
\institute[IIT Bombay] {Department of Aerospace Engineering\\IIT Bombay}
-\date[] {1 November, 2009\\Day 2, Session 5}
-
+\date[] {8 November, 2009\\Day 2, Session 3}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-%\pgfdeclareimage[height=0.75cm]{iitblogo}{iitblogo}
-%\logo{\pgfuseimage{iitblogo}}
+%\pgfdeclareimage[height=0.75cm]{iitmlogo}{iitmlogo}
+%\logo{\pgfuseimage{iitmlogo}}
-\AtBeginSection[]
-{
- \begin{frame}<beamer>
- \frametitle{Outline}
- \tableofcontents[currentsection,currentsubsection]
- \end{frame}
-}
%% Delete this, if you do not want the table of contents to pop up at
%% the beginning of each subsection:
@@ -132,12 +102,19 @@
\tableofcontents[currentsection,currentsubsection]
\end{frame}
}
+
+% If you wish to uncover everything in a step-wise fashion, uncomment
+% the following command:
+%\beamerdefaultoverlayspecification{<+->}
+
+%\includeonlyframes{current,current1,current2,current3,current4,current5,current6}
+
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% DOCUMENT STARTS
\begin{document}
\begin{frame}
- \maketitle
+ \titlepage
\end{frame}
\begin{frame}
@@ -146,413 +123,325 @@
% You might wish to add the option [pausesections]
\end{frame}
-\section{3D Data Visualization}
+\section{Functions}
+\subsection{Default arguments}
+\begin{frame}[fragile]
+ \frametitle{Functions: default arguments}
+ \begin{lstlisting}
+In []: greet = 'hello world'
-\begin{frame}
- \frametitle{What is visualization?}
- \Large
- \begin{center}
- Visual representation of data
- \end{center}
+In []: greet.split()
+Out[]: ['hello', 'world']
+
+In []: line = 'Rossum, Guido, 54, 46, 55'
+
+In []: line.split(',')
+Out[]: ['Rossum', ' Guido', ' 54',
+ ' 46', ' 55']
+ \end{lstlisting}
\end{frame}
+\begin{frame}[fragile]
+ \frametitle{Functions: default arguments \ldots}
+ \small
+ \begin{lstlisting}
+def ask_ok(prompt, complaint='Yes or no!'):
+ while True:
+ ok = raw_input(prompt)
+ if ok in ('y', 'ye', 'yes'):
+ return True
+ if ok in ('n', 'no', 'nop',
+ 'nope'):
+ return False
+ print complaint
-%% \begin{frame}
-%% \frametitle{Is this new?}
-%% \begin{center}
-%% We have moved from:
-%% \end{center}
-%% \begin{columns}
-%% \column{}
-%% \hspace*{-1in}
-%% \includegraphics[width=1.75in,height=1.75in, interpolate=true]{data/3832}
-%% \column{}\hspace*{-0.25in}
-%% To
-%% \column{}
-%% \hspace*{-1in}
-%% \includegraphics[width=1.75in, height=1.75in, interpolate=true]{data/torus}
-%% \end{columns}
-%% \end{frame}
+ask_ok('?')
+ask_ok('?', '[Y/N]')
+ \end{lstlisting}
+\end{frame}
-\begin{frame}
- \frametitle{3D visualization}
- \Large
- \begin{center}
- Harder but important
- \end{center}
+\subsection{Keyword arguments}
+\begin{frame}[fragile]
+ \frametitle{Functions: Keyword arguments}
+We have seen the following
+ \begin{lstlisting}
+In []: legend(['sin(2y)'],
+ loc='center')
+In []: plot(y, sin(y), 'g',
+ linewidth=2)
+In []: annotate('local max',
+ xy=(1.5, 1))
+In []: pie(science.values(),
+ labels=science.keys())
+ \end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{Functions: keyword arguments \ldots}
+ \small
+ \begin{lstlisting}
+def ask_ok(prompt, complaint='Yes or no!'):
+ while True:
+ ok = raw_input(prompt)
+ if ok in ('y', 'ye', 'yes'):
+ return True
+ if ok in ('n', 'no', 'nop',
+ 'nope'):
+ return False
+ print complaint
+
+ask_ok(prompt='?')
+ask_ok(prompt='?', complaint='[y/n]')
+ask_ok(complaint='[y/n]', prompt='?')
+\end{lstlisting}
\end{frame}
+\subsection{Built-in functions}
\begin{frame}
- \frametitle{Is this Graphics?}
- \Large
- \begin{center}
- Visualization is about data!
- \end{center}
+ {Before writing a function}
+ \begin{itemize}
+ \item Variety of builtin functions are available
+ \item \typ{abs, any, all, len, max, min}
+ \item \typ{pow, range, sum, type}
+ \item Refer here:
+ \url{http://docs.python.org/library/functions.html}
+ \end{itemize}
+ \inctime{10}
+\end{frame}
+
+\subsection{Exercises}
+\begin{frame}{Problem set 3: Problem 3.1}
+ Write a function to return the gcd of two numbers.
\end{frame}
-\begin{frame}
- \frametitle{Examples: trajectory in space}
- \Large
- \begin{center}
- \pgfimage[width=2.5in]{MEDIA/m2/mlab/plot3d_ex}
- \end{center}
+\begin{frame}{Problem 3.2}
+Write a program to print all primitive pythagorean triads (a, b, c) where a, b are in the range 1---100 \\
+A pythagorean triad $(a,b,c)$ has the property $a^2 + b^2 = c^2$.\\By primitive we mean triads that do not `depend' on others. For example, (4,3,5) is a variant of (3,4,5) and hence is not primitive. And (10,24,26) is easily derived from (5,12,13) and is also not primitive.
+\end{frame}
+
+\begin{frame}{Problem 3.3}
+ Write a program that generates a list of all four digit numbers that have all their digits even and are perfect squares.\newline\\\emph{For example, the output should include 6400 but not 8100 (one digit is odd) or 4248 (not a perfect square).}
+\inctime{15}
+\end{frame}
+
+\section{Modules}
+\begin{frame}[fragile]
+ \frametitle{\typ{from} \ldots \typ{import} magic}
+ \begin{lstlisting}
+from scipy.interpolate import splrep
+from scipy.interpolate import splev
+
+from scipy.integrate import quad
+from scipy.integrate import odeint
+
+from scipy.optimize import fsolve
+ \end{lstlisting}
+\emphbar{All the above statements import one function into your namespace}
\end{frame}
-\begin{frame}
- \frametitle{Examples: Fire in a room}
- \Large
- \begin{center}
- Demo of data
- \end{center}
-\inctime{10}
+\begin{frame}[fragile]
+ \frametitle{Running scripts from command line}
+ \small
+ \begin{itemize}
+ \item Start cmd
+ \item cd to Desktop
+ \item python sine\_plot.py
+ \end{itemize}
+ \pause
+ \begin{lstlisting}
+Traceback (most recent call last):
+ File "sine_plot.py", line 1, in <module>
+ x = linspace(-5*pi, 5*pi, 500)
+NameError: name 'linspace' is not defined
+ \end{lstlisting}
\end{frame}
-\section{Tools available}
-
-\subsection{mlab}
+\begin{frame}[fragile]
+ \frametitle{Remedy}
+ \emphbar{Adding what lines to sine\_plot.py makes this program work?}
+ \begin{lstlisting}
+from scipy import *
+ \end{lstlisting}
+\alert{Now run python sine\_plot.py again!}
+ \pause
+ \begin{lstlisting}
+Traceback (most recent call last):
+ File "sine_plot.py", line 4, in <module>
+ plot(x, x, 'b')
+NameError: name 'plot' is not defined
+ \end{lstlisting}
+\end{frame}
-\begin{frame}
- {Overview}
- \Large
- \begin{itemize}
- \item Simple
- \item Convenient
- \item Full-featured
+\begin{frame}[fragile]
+ \frametitle{Remedy \ldots}
+ \emphbar{What should we add now?}
+ \begin{lstlisting}
+from pylab import *
+ \end{lstlisting}
+\alert{Now run python sine\_plot.py again!!}
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{Modules}
+ \begin{itemize}
+ \item The \kwrd{import} keyword ``loads'' a module
+ \item One can also use:
+ \begin{lstlisting}
+In []: from scipy import *
+In []: from scipy import linspace
+ \end{lstlisting}
+ \item What is the difference?
+ \item \alert{Use the former only in interactive mode}
\end{itemize}
\end{frame}
\begin{frame}[fragile]
-
- \frametitle{Getting started}
- \myemph{\Large Vanilla:}
- \begin{lstlisting}[language=bash]
- $ ipython -wthread
- \end{lstlisting}
- \myemph{\Large with Pylab:}
- \begin{lstlisting}[language=bash]
- $ ipython -pylab -wthread
- \end{lstlisting}
-\end{frame}
-
-\begin{frame}[fragile]
- \frametitle{Using mlab}
-
- \begin{lstlisting}
-In []:from enthought.mayavi import mlab
- \end{lstlisting}
-
- \vspace*{0.5in}
-
- \myemph{\Large Try these}
-
- \vspace*{0.25in}
-
- \begin{lstlisting}
-In []: mlab.test_<TAB>
-In []: mlab.test_contour3d()
-In []: mlab.test_contour3d??
- \end{lstlisting}
-\end{frame}
-
-\begin{frame}
- {Exploring the view}
- \begin{columns}
- \column{0.6\textwidth}
- \pgfimage[width=3in]{MEDIA/m2/contour3d}
- \column{0.4\textwidth}
- \begin{itemize}
- \item Mouse
- \item Keyboard
- \item Toolbar
- \item Mayavi icon\pgfimage[width=0.2in]{MEDIA/m2/m2_icon}
- \end{itemize}
- \end{columns}
-\end{frame}
-
-\begin{frame}[fragile]
- \frametitle{\mlab\ plotting functions}
- \begin{columns}
- \column{0.25\textwidth}
- \myemph{\Large 0D data}
- \column{0.5\textwidth}
- \pgfimage[width=2in]{MEDIA/m2/mlab/points3d_ex}
- \end{columns}
-
- \begin{lstlisting}
-In []: t = linspace(0, 2*pi, 50)
-In []: u = cos(t) * pi
-In []: x, y, z = sin(u), cos(u), sin(t)
- \end{lstlisting}
- \emphbar{\PythonCode{In []: mlab.points3d(x, y, z)}}
-\end{frame}
-
-\begin{frame}
- \begin{columns}
- \column{0.25\textwidth}
- \myemph{\Large 1D data}
- \column{0.5\textwidth}
- \pgfimage[width=2.5in]{MEDIA/m2/mlab/plot3d_ex}
- \end{columns}
- \emphbar{\PythonCode{In []: mlab.plot3d(x, y, z, t)}}
+ \frametitle{Package hierarchies}
+ \begin{lstlisting}
+from scipy.interpolate import splev
- Plots lines between the points
-
-\end{frame}
-
-\begin{frame}[fragile]
- \begin{columns}
- \column{0.25\textwidth}
- \myemph{\Large 2D data}
- \column{0.5\textwidth}
- \pgfimage[width=2in]{MEDIA/m2/mlab/surf_ex}
- \end{columns}
- \begin{lstlisting}
-In []: x, y = mgrid[-3:3:100j,-3:3:100j]
-In []: z = sin(x*x + y*y)
- \end{lstlisting}
-
- \emphbar{\PythonCode{In []: mlab.surf(x, y, z)}}
-
- \alert{Assumes the points are rectilinear}
-
-\end{frame}
-
-\begin{frame}[fragile]
- \frametitle{mgrid}
- \begin{lstlisting}
-In []: mgrid[0:3,0:3]
-Out[]:
-array([[[0, 0, 0],
- [1, 1, 1],
- [2, 2, 2]],
-
- [[0, 1, 2],
- [0, 1, 2],
- [0, 1, 2]]])
+from scipy.integrate import quad
-In []: mgrid[-1:1:5j]
-Out[]: array([-1., -0.5, 0., 0.5, 1.])
-\end{lstlisting}
-\end{frame}
-
-\begin{frame}[fragile]
- \frametitle{Example}
- \begin{lstlisting}
-In []: x, y = mgrid[-1:1:5j, -1:1:5j]
-In []: z = x*x + y*y
-
-In []: z
-Out[]:
-array([[ 2. , 1.25, 1. , 1.25, 2. ],
- [ 1.25, 0.5 , 0.25, 0.5 , 1.25],
- [ 1. , 0.25, 0. , 0.25, 1. ],
- [ 1.25, 0.5 , 0.25, 0.5 , 1.25],
- [ 2. , 1.25, 1. , 1.25, 2. ]])
-\end{lstlisting}
-\end{frame}
-
-\begin{frame}[fragile]
- \myemph{\Large 2D data: \texttt{mlab.mesh}}
- \vspace*{0.25in}
-
- \emphbar{\PythonCode{In []: mlab.mesh(x, y, z)}}
-
- \alert{Points needn't be regular}
-
- \vspace*{0.25in}
-\begin{lstlisting}
-In []: phi, theta = mgrid[0:pi:20j,
-... 0:2*pi:20j]
-In []: x = sin(phi)*cos(theta)
-In []: y = sin(phi)*sin(theta)
-In []: z = cos(phi)
-In []: mlab.mesh(x, y, z,
-... representation=
-... 'wireframe')
-\end{lstlisting}
-
+from scipy.optimize import fsolve
+ \end{lstlisting}
\end{frame}
\begin{frame}[fragile]
+ \frametitle{from \ldots import in a conventional way!}
+ \small
+ \begin{lstlisting}
+from scipy import linspace, pi, sin
+from pylab import plot, legend, annotate
+from pylab import xlim, ylim
- \begin{columns}
- \column{0.25\textwidth}
- \myemph{\Large 3D data}
- \column{0.5\textwidth}
- \pgfimage[width=1.5in]{MEDIA/m2/mlab/contour3d}\\
- \end{columns}
-\begin{lstlisting}
-In []: x, y, z = mgrid[-5:5:64j,
-... -5:5:64j,
-... -5:5:64j]
-In []: mlab.contour3d(x*x*0.5 + y*y +
- z*z*2)
-\end{lstlisting}
+x = linspace(-5*pi, 5*pi, 500)
+plot(x, x, 'b')
+plot(x, -x, 'b')
+plot(x, sin(x), 'g', linewidth=2)
+plot(x, x*sin(x), 'r', linewidth=3)
+legend(['x', '-x', 'sin(x)', 'xsin(x)'])
+annotate('origin', xy = (0, 0))
+xlim(-5*pi, 5*pi)
+ylim(-5*pi, 5*pi)
+ \end{lstlisting}
\end{frame}
\begin{frame}[fragile]
-
- \myemph{\Large 3D vector data: \PythonCode{mlab.quiver3d}}
- \vspace*{0.25in}
-
- \pgfimage[width=2in]{MEDIA/m2/mlab/quiver3d_ex}\\
-
-\begin{lstlisting}
-In []: mlab.test_quiver3d()
-\end{lstlisting}
-
-\emphbar{\PythonCode{obj = mlab.quiver3d(x, y, z, u, v, w)}}
-\inctime{20}
-\end{frame}
-
-
-\subsection{Mayavi2}
-
-\begin{frame}
- \frametitle{Introduction to Mayavi}
- \begin{itemize}
- \item Most scientists not interested in details of visualization
- \item Visualization of data files with a nice UI
- \item Interactive visualization of data (think Matlab)
- \item Embedding visualizations in applications
- \item Customization
- \end{itemize}
- \pause
- \begin{block}{The Goal}
- Provide a \alert{flexible} library/app for all of these needs!
- \end{block}
-\end{frame}
-
-\begin{frame}
- {Overview of features}
- \vspace*{-0.3in}
- \begin{center}
- \hspace*{-0.2in}\pgfimage[width=5in]{MEDIA/m2/m2_app3_3}
- \end{center}
-\end{frame}
-
-
-\begin{frame}
- \frametitle{Mayavi in applications}
- \vspace*{-0.3in}
- \begin{center}
- \hspace*{-0.2in}\pgfimage[width=4.5in]{MEDIA/m2/m2_envisage}
- \end{center}
-\end{frame}
-
-\begin{frame}
- \frametitle{Live in your dialogs}
- \vspace*{0.1in}
- \begin{center}
- \hspace*{-0.2in}\pgfimage[width=2.5in]{MEDIA/m2/mlab_tui}
- \end{center}
-\end{frame}
-
-\begin{frame}
- {Exploring the documentation}
- \begin{center}
- \pgfimage[width=4in]{MEDIA/m2/m2_ug_doc}
- \end{center}
-\end{frame}
-
+ \frametitle{from \ldots import in a conventional way!}
+ \small
+ \begin{lstlisting}
+import scipy
+import pylab
-\begin{frame}
- \frametitle{Summary}
- \begin{itemize}
- \item \url{http://code.enthought.com/projects/mayavi}
- \item Uses VTK (\url{www.vtk.org})
- \item BSD license
- \item Linux, win32 and Mac OS X
- \item Highly scriptable
- \item Embed in Traits UIs (wxPython and PyQt4)
- \item Envisage Plugins
- \item Debian/Ubuntu/Fedora
- \item \alert{Pythonic}
- \end{itemize}
-
- \inctime{10}
-
-\end{frame}
-
-\begin{frame}
- {Getting hands dirty!}
-
- \begin{block}{Motivational problem}
- Atmospheric data of temperature over the surface of the earth.
- Let temperature ($T$) vary linearly with height ($z$):
- \begin{center}
- $T = 288.15 - 6.5z$
- \end{center}
- \end{block}
-\end{frame}
-
-\begin{frame}[fragile]
- \frametitle{Simple solution}
-
- \begin{lstlisting}
-lat = linspace(-89, 89, 37)
-lon = linspace(0, 360, 37)
-z = linspace(0, 100, 11)
- \end{lstlisting}
-\pause
- \begin{lstlisting}
-x, y, z = mgrid[0:360:37j,-89:89:37j,
- 0:100:11j]
-t = 288.15 - 6.5*z
-mlab.contour3d(x, y, z, t)
-mlab.outline()
-mlab.colorbar()
- \end{lstlisting}
-\end{frame}
-
-\begin{frame}[fragile]
- \frametitle{Exercise: Lorenz equation}
- \begin{columns}
- \column{0.25\textwidth}
- \begin{eqnarray*}
- \frac{d x}{dt} &=& s (y-x)\\
- \frac{d y}{d t} &=& rx -y -xz\\
- \frac{d z}{d t} &=& xy - bz\\
- \end{eqnarray*}
- \column{0.25\textwidth}
- Let $s=10,$
- $r=28,$
- $b=8./3.$
- \end{columns}
- \structure{\Large Region of interest}
- \begin{lstlisting}
-x, y, z = mgrid[-50:50:20j,-50:50:20j,
- -10:60:20j]
- \end{lstlisting}
-\inctime{20}
-
-\end{frame}
-\begin{frame}[fragile]
- \frametitle{Solution}
- \begin{lstlisting}
-def lorenz(x,y,z,s=10.,r=28.,b=8./3.):
- u = s*(y-x)
- v = r*x-y-x*z
- w = x*y-b*z
- return u,v,w
-x,y,z = mgrid [-50:50:20j,-50:50:20j,
- -10:60:20j ]
-u,v,w = lorenz( x , y , z )
-# Your plot here
-#
-mlab.show()
-
+x = scipy.linspace(-5*scipy.pi, 5*scipy.pi, 500)
+pylab.plot(x, x, 'b')
+pylab.plot(x, -x, 'b')
+pylab.plot(x, scipy.sin(x), 'g', linewidth=2)
+pylab.plot(x, x*scipy.sin(x), 'r', linewidth=3)
+pylab.legend(['x', '-x', 'sin(x)', 'xsin(x)'])
+pylab.annotate('origin', xy = (0, 0))
+pylab.xlim(-5*scipy.pi, 5*scipy.pi)
+pylab.ylim(-5*scipy.pi, 5*scipy.pi)
\end{lstlisting}
\end{frame}
\begin{frame}
- \frametitle{We have covered:}
+ \frametitle{Modules: Standard library}
\begin{itemize}
- \item Need of visualization.
- \item Using mlab to create 3 D plots.
- \item Mayavi Toolkit.
+ \item Very powerful, ``Batteries included''
+ \item Some standard modules:
+ \begin{itemize}
+ \item Math: \typ{math}, \typ{random}
+ \item Internet access: \typ{urllib2}, \typ{smtplib}
+ \item System, Command line arguments: \typ{sys}
+ \item Operating system interface: \typ{os}
+ \item Regular expressions: \typ{re}
+ \item Compression: \typ{gzip}, \typ{zipfile}, and \typ{tarfile}
+ \item And a whole lot more!
+ \end{itemize}
+ \item Check out the Python Library reference:
+ \url{http://docs.python.org/library/}
+ \end{itemize}
+\inctime{5}
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{Modules of special interest}
+ \begin{description}[matplotlibfor2d]
+ \item[\typ{pylab}] Easy, interactive, 2D plotting
+
+ \item[\typ{scipy}] arrays, statistics, optimization, integration, linear
+ algebra, Fourier transforms, signal and image processing,
+ genetic algorithms, ODE solvers, special functions, and more
+
+ \item[\typ{Mayavi}] Easy, interactive, 3D plotting
+ \end{description}
+\end{frame}
+
+\section{Objects}
+\begin{frame}{Everything is an Object!}
+ \begin{itemize}
+ \item \typ{int}
+ \item \typ{float}
+ \item \typ{str}
+ \item \typ{list}
+ \item \typ{tuple}
+ \item \typ{string}
+ \item \typ{dictionary}
+ \item \typ{function}
+ \item User defined class is also an object!
+ \end{itemize}
+\end {frame}
+
+\begin{frame}[fragile]
+\frametitle{Using Objects}
+ \begin{itemize}
+ \item Creating Objects
+ \begin{itemize}
+ \item Initialization
+ \end{itemize}
+ \begin{lstlisting}
+In []: a = str()
+
+In []: b = "Hello World"
+ \end{lstlisting}
+ \item Object Manipulation
+ \begin{itemize}
+ \item Object methods
+ \item ``.'' operator
+ \end{itemize}
+ \begin{lstlisting}
+In []: "Hello World".split()
+Out[]: ['Hello', 'World']
+ \end{lstlisting}
\end{itemize}
\end{frame}
-\end{document}
+\begin{frame}[fragile]
+ \frametitle{Objects provide consistency}
+ \small
+ \begin{lstlisting}
+for element in (1, 2, 3):
+ print element
+for key in {'one':1, 'two':2}:
+ print key
+for char in "123":
+ print char
+for line in open("myfile.txt"):
+ print line
+for line in urllib2.urlopen('http://site.com'):
+ print line
+ \end{lstlisting}
+ \inctime{10}
+\end{frame}
+\begin{frame}
+ \frametitle{What did we learn?}
+ \begin{itemize}
+ \item Functions: Default and Keyword arguments
+ \item Modules
+ \item Objects
+ \end{itemize}
+\end{frame}
+
+\end{document}
\ No newline at end of file
--- a/day2/session4.tex Fri Nov 06 17:56:22 2009 +0530
+++ b/day2/session4.tex Fri Nov 06 18:33:08 2009 +0530
@@ -74,7 +74,7 @@
\newcommand{\tvtk}{\texttt{tvtk}}
\newcommand{\mlab}{\texttt{mlab}}
-\newcommand{\typ}[1]{\lstinline{#1}}
+
\newcounter{time}
\setcounter{time}{0}
\newcommand{\inctime}[1]{\addtocounter{time}{#1}{\vspace*{0.1in}\tiny \thetime\ m}}
@@ -95,12 +95,13 @@
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Title page
-\title[Python Development]{Python Development}
+\title[3D Plotting]{3D data Visualization}
\author[FOSSEE] {FOSSEE}
\institute[IIT Bombay] {Department of Aerospace Engineering\\IIT Bombay}
-\date[] {1 November, 2009\\Day 2, Session 3}
+\date[] {1 November, 2009\\Day 2, Session 5}
+
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%\pgfdeclareimage[height=0.75cm]{iitblogo}{iitblogo}
@@ -109,8 +110,7 @@
\AtBeginSection[]
{
\begin{frame}<beamer>
- \frametitle{Outline}
- \Large
+ \frametitle{Outline}
\tableofcontents[currentsection,currentsubsection]
\end{frame}
}
@@ -140,423 +140,419 @@
\maketitle
\end{frame}
-\section{Tests: Getting started}
-\begin{frame}[fragile]
- \frametitle{gcd revisited!}
- \begin{itemize}
- \item Open gcd.py
- \end{itemize}
-\begin{lstlisting}
- def gcd(a, b):
- if a % b == 0:
- return b
- return gcd(b, a%b)
+\begin{frame}
+ \frametitle{Outline}
+ \tableofcontents
+ % You might wish to add the option [pausesections]
+\end{frame}
+
+\section{3D Data Visualization}
+
+\begin{frame}
+ \frametitle{What is visualization?}
+ \Large
+ \begin{center}
+ Visual representation of data
+ \end{center}
+\end{frame}
+
- print gcd(15, 65)
- print gcd(16, 76)
-\end{lstlisting}
- \begin{itemize}
- \item python gcd.py
- \end{itemize}
+%% \begin{frame}
+%% \frametitle{Is this new?}
+%% \begin{center}
+%% We have moved from:
+%% \end{center}
+%% \begin{columns}
+%% \column{}
+%% \hspace*{-1in}
+%% \includegraphics[width=1.75in,height=1.75in, interpolate=true]{data/3832}
+%% \column{}\hspace*{-0.25in}
+%% To
+%% \column{}
+%% \hspace*{-1in}
+%% \includegraphics[width=1.75in, height=1.75in, interpolate=true]{data/torus}
+%% \end{columns}
+%% \end{frame}
+
+\begin{frame}
+ \frametitle{3D visualization}
+ \Large
+ \begin{center}
+ Harder but important
+ \end{center}
\end{frame}
-\begin{frame}[fragile]
- \frametitle{Find lcm using our gcd module}
- \begin{itemize}
- \item Open lcm.py
- \item $lcm = \frac{a*b}{gcd(a,b)}$
- \end{itemize}
-\begin{lstlisting}
- from gcd import gcd
- def lcm(a, b):
- return (a * b) / gcd(a, b)
-
- print lcm(14, 56)
-\end{lstlisting}
- \begin{itemize}
- \item python lcm.py
- \end{itemize}
- \begin{lstlisting}
-5
-4
-56
- \end{lstlisting}
+\begin{frame}
+ \frametitle{Is this Graphics?}
+ \Large
+ \begin{center}
+ Visualization is about data!
+ \end{center}
+\end{frame}
+
+\begin{frame}
+ \frametitle{Examples: trajectory in space}
+ \Large
+ \begin{center}
+ \pgfimage[width=2.5in]{MEDIA/m2/mlab/plot3d_ex}
+ \end{center}
+\end{frame}
+
+\begin{frame}
+ \frametitle{Examples: Fire in a room}
+ \Large
+ \begin{center}
+ Demo of data
+ \end{center}
+\inctime{10}
\end{frame}
-\begin{frame}[fragile]
- \frametitle{Writing stand-alone module}
-Edit gcd.py file to:
-\begin{lstlisting}
- def gcd(a, b):
- if a % b == 0:
- return b
- return gcd(b, a%b)
+\section{Tools available}
+
+\subsection{mlab}
- if __name__ == "__main__":
- print gcd(15, 65)
- print gcd(16, 76)
-\end{lstlisting}
- \begin{itemize}
- \item python gcd.py
- \item python lcm.py
- \end{itemize}
+\begin{frame}
+ {Overview}
+ \Large
+ \begin{itemize}
+ \item Simple
+ \item Convenient
+ \item Full-featured
+ \end{itemize}
+\end{frame}
+
+\begin{frame}[fragile]
+
+ \frametitle{Getting started}
+ \myemph{\Large Vanilla:}
+ \begin{lstlisting}[language=bash]
+ $ ipython -wthread
+ \end{lstlisting}
+ \myemph{\Large with Pylab:}
+ \begin{lstlisting}[language=bash]
+ $ ipython -pylab -wthread
+ \end{lstlisting}
\end{frame}
\begin{frame}[fragile]
- \frametitle{More use of main}
- For automating tests.
- \begin{lstlisting}
-if __name__ == '__main__':
- for line in open('numbers.txt'):
- numbers = line.split()
- x = int(numbers[0])
- y = int(numbers[1])
- result = (int(numbers[2]))
- assert gcd(x, y) == result
- \end{lstlisting}
+ \frametitle{Using mlab}
+
+ \begin{lstlisting}
+In []:from enthought.mayavi import mlab
+ \end{lstlisting}
+
+ \vspace*{0.5in}
+
+ \myemph{\Large Try these}
+
+ \vspace*{0.25in}
+
+ \begin{lstlisting}
+In []: mlab.test_<TAB>
+In []: mlab.test_contour3d()
+In []: mlab.test_contour3d??
+ \end{lstlisting}
\end{frame}
-\section{Coding Style}
-\begin{frame}{Readability and Consistency}
- \begin{itemize}
- \item Readability Counts!\\Code is read more often than its written.
- \item Consistency!
- \item Know when to be inconsistent.
- \end{itemize}
-\end{frame}
-
-\begin{frame}[fragile] \frametitle{A question of good style}
- \begin{lstlisting}
- amount = 12.68
- denom = 0.05
- nCoins = round(amount/denom)
- rAmount = nCoins * denom
- \end{lstlisting}
- \pause
- \begin{block}{Style Rule \#1}
- Naming is 80\% of programming
- \end{block}
+\begin{frame}
+ {Exploring the view}
+ \begin{columns}
+ \column{0.6\textwidth}
+ \pgfimage[width=3in]{MEDIA/m2/contour3d}
+ \column{0.4\textwidth}
+ \begin{itemize}
+ \item Mouse
+ \item Keyboard
+ \item Toolbar
+ \item Mayavi icon\pgfimage[width=0.2in]{MEDIA/m2/m2_icon}
+ \end{itemize}
+ \end{columns}
\end{frame}
\begin{frame}[fragile]
- \frametitle{Code Layout}
- \begin{itemize}
- \item Indentation
- \item Tabs or Spaces??
- \item Maximum Line Length
- \item Blank Lines
- \item Encodings
- \end{itemize}
-\end{frame}
+ \frametitle{\mlab\ plotting functions}
+ \begin{columns}
+ \column{0.25\textwidth}
+ \myemph{\Large 0D data}
+ \column{0.5\textwidth}
+ \pgfimage[width=2in]{MEDIA/m2/mlab/points3d_ex}
+ \end{columns}
-\begin{frame}{Whitespaces in Expressions}
- \begin{itemize}
- \item When to use extraneous whitespaces??
- \item When to avoid extra whitespaces??
- \item Use one statement per line
- \end{itemize}
+ \begin{lstlisting}
+In []: t = linspace(0, 2*pi, 50)
+In []: u = cos(t) * pi
+In []: x, y, z = sin(u), cos(u), sin(t)
+ \end{lstlisting}
+ \emphbar{\PythonCode{In []: mlab.points3d(x, y, z)}}
\end{frame}
-\begin{frame}{Comments}
- \begin{itemize}
- \item No comments better than contradicting comments
- \item Block comments
- \item Inline comments
- \end{itemize}
-\end{frame}
+\begin{frame}
+ \begin{columns}
+ \column{0.25\textwidth}
+ \myemph{\Large 1D data}
+ \column{0.5\textwidth}
+ \pgfimage[width=2.5in]{MEDIA/m2/mlab/plot3d_ex}
+ \end{columns}
+ \emphbar{\PythonCode{In []: mlab.plot3d(x, y, z, t)}}
-\begin{frame}{Docstrings}
- \begin{itemize}
- \item When to write docstrings?
- \item Ending the docstrings
- \item One liner docstrings
- \end{itemize}
-More information at PEP8: http://www.python.org/dev/peps/pep-0008/
-\inctime{5}
-\end{frame}
-
-\section{Debugging}
-\subsection{Errors and Exceptions}
-\begin{frame}[fragile]
- \frametitle{Errors}
- \begin{lstlisting}
-In []: while True print 'Hello world'
- \end{lstlisting}
-\pause
- \begin{lstlisting}
- File "<stdin>", line 1, in ?
- while True print 'Hello world'
- ^
-SyntaxError: invalid syntax
-\end{lstlisting}
+ Plots lines between the points
+
\end{frame}
\begin{frame}[fragile]
- \frametitle{Exceptions}
- \begin{lstlisting}
-In []: print spam
-\end{lstlisting}
-\pause
-\begin{lstlisting}
-Traceback (most recent call last):
- File "<stdin>", line 1, in <module>
-NameError: name 'spam' is not defined
-\end{lstlisting}
+ \begin{columns}
+ \column{0.25\textwidth}
+ \myemph{\Large 2D data}
+ \column{0.5\textwidth}
+ \pgfimage[width=2in]{MEDIA/m2/mlab/surf_ex}
+ \end{columns}
+ \begin{lstlisting}
+In []: x, y = mgrid[-3:3:100j,-3:3:100j]
+In []: z = sin(x*x + y*y)
+ \end{lstlisting}
+
+ \emphbar{\PythonCode{In []: mlab.surf(x, y, z)}}
+
+ \alert{Assumes the points are rectilinear}
+
\end{frame}
\begin{frame}[fragile]
- \frametitle{Exceptions}
- \begin{lstlisting}
-In []: 1 / 0
-\end{lstlisting}
-\pause
-\begin{lstlisting}
-Traceback (most recent call last):
- File "<stdin>", line 1, in <module>
-ZeroDivisionError: integer division
-or modulo by zero
+ \frametitle{mgrid}
+ \begin{lstlisting}
+In []: mgrid[0:3,0:3]
+Out[]:
+array([[[0, 0, 0],
+ [1, 1, 1],
+ [2, 2, 2]],
+
+ [[0, 1, 2],
+ [0, 1, 2],
+ [0, 1, 2]]])
+
+In []: mgrid[-1:1:5j]
+Out[]: array([-1., -0.5, 0., 0.5, 1.])
\end{lstlisting}
\end{frame}
\begin{frame}[fragile]
- \frametitle{Handling Exceptions}
- Python uses \typ{try} and \typ{except} clause.
- %%Revisiting the raw\_input
+ \frametitle{Example}
\begin{lstlisting}
-a = raw_input('Enter number(Q to quit):')
-try:
- num = int(a)
- print num
-except:
- if a == 'Q':
- print 'Exiting...'
- else:
- print 'Wrong input!'
- \end{lstlisting}
-
-
-\end{frame}
+In []: x, y = mgrid[-1:1:5j, -1:1:5j]
+In []: z = x*x + y*y
-%% \begin{frame}[fragile]
-%% \frametitle{Solving it with \typ{try} and \typ{except}}
-%% \vspace{-0.2in}
-%% \begin{lstlisting}
-%% highest = 0
-%% for record in open('sslc1.txt'):
-%% fields = record.split(';')
-%% try:
-%% total = 0
-%% for score_str in fields[3:8]:
-%% score = int(score_str)
-%% total += score
-%% if total > highest:
-%% highest = total
-%% except:
-%% pass
-%% print highest
-%% \end{lstlisting}
-%% \end{frame}
-\subsection{Strategy}
-\begin{frame}[fragile]
- \frametitle{Debugging effectively}
- \begin{itemize}
- \item \typ{print} based strategy
- \item Process:
- \end{itemize}
-\begin{center}
-\pgfimage[interpolate=true,width=5cm,height=5cm]{DebugginDiagram.png}
-\end{center}
+In []: z
+Out[]:
+array([[ 2. , 1.25, 1. , 1.25, 2. ],
+ [ 1.25, 0.5 , 0.25, 0.5 , 1.25],
+ [ 1. , 0.25, 0. , 0.25, 1. ],
+ [ 1.25, 0.5 , 0.25, 0.5 , 1.25],
+ [ 2. , 1.25, 1. , 1.25, 2. ]])
+\end{lstlisting}
\end{frame}
\begin{frame}[fragile]
- \frametitle{Debugging effectively}
- \begin{itemize}
- \item Using \typ{\%debug} in IPython
- \end{itemize}
+ \myemph{\Large 2D data: \texttt{mlab.mesh}}
+ \vspace*{0.25in}
+
+ \emphbar{\PythonCode{In []: mlab.mesh(x, y, z)}}
+
+ \alert{Points needn't be regular}
+
+ \vspace*{0.25in}
+\begin{lstlisting}
+In []: phi, theta = mgrid[0:pi:20j,
+... 0:2*pi:20j]
+In []: x = sin(phi)*cos(theta)
+In []: y = sin(phi)*sin(theta)
+In []: z = cos(phi)
+In []: mlab.mesh(x, y, z,
+... representation=
+... 'wireframe')
+\end{lstlisting}
+
+\end{frame}
+
+\begin{frame}[fragile]
+
+ \begin{columns}
+ \column{0.25\textwidth}
+ \myemph{\Large 3D data}
+ \column{0.5\textwidth}
+ \pgfimage[width=1.5in]{MEDIA/m2/mlab/contour3d}\\
+ \end{columns}
+\begin{lstlisting}
+In []: x, y, z = mgrid[-5:5:64j,
+... -5:5:64j,
+... -5:5:64j]
+In []: mlab.contour3d(x*x*0.5 + y*y +
+ z*z*2)
+\end{lstlisting}
\end{frame}
\begin{frame}[fragile]
-\frametitle{Debugging in IPython}
-\small
+
+ \myemph{\Large 3D vector data: \PythonCode{mlab.quiver3d}}
+ \vspace*{0.25in}
+
+ \pgfimage[width=2in]{MEDIA/m2/mlab/quiver3d_ex}\\
+
\begin{lstlisting}
-In []: import mymodule
-In []: mymodule.test()
----------------------------------------------
-NameError Traceback (most recent call last)
-<ipython console> in <module>()
-mymodule.py in test()
- 1 def test():
-----> 2 print spam
-NameError: global name 'spam' is not defined
+In []: mlab.test_quiver3d()
+\end{lstlisting}
+
+\emphbar{\PythonCode{obj = mlab.quiver3d(x, y, z, u, v, w)}}
+\inctime{20}
+\end{frame}
+
+
+\subsection{Mayavi2}
-In []: %debug
-> mymodule.py(2)test()
- 0 print spam
-ipdb>
-\end{lstlisting}
-\inctime{15}
+\begin{frame}
+ \frametitle{Introduction to Mayavi}
+ \begin{itemize}
+ \item Most scientists not interested in details of visualization
+ \item Visualization of data files with a nice UI
+ \item Interactive visualization of data (think Matlab)
+ \item Embedding visualizations in applications
+ \item Customization
+ \end{itemize}
+ \pause
+ \begin{block}{The Goal}
+ Provide a \alert{flexible} library/app for all of these needs!
+ \end{block}
+\end{frame}
+
+\begin{frame}
+ {Overview of features}
+ \vspace*{-0.3in}
+ \begin{center}
+ \hspace*{-0.2in}\pgfimage[width=5in]{MEDIA/m2/m2_app3_3}
+ \end{center}
\end{frame}
-\subsection{Exercise}
-\begin{frame}[fragile]
-\frametitle{Debugging: Exercise}
-\small
-\begin{lstlisting}
-science = {}
-for record in open('sslc1.txt'):
- fields = record.split(';')
- region_code = fields[0].strip()
+\begin{frame}
+ \frametitle{Mayavi in applications}
+ \vspace*{-0.3in}
+ \begin{center}
+ \hspace*{-0.2in}\pgfimage[width=4.5in]{MEDIA/m2/m2_envisage}
+ \end{center}
+\end{frame}
- score_str = fields[6].strip()
- score = int(score_str) if score_str != 'AA'
- else 0
+\begin{frame}
+ \frametitle{Live in your dialogs}
+ \vspace*{0.1in}
+ \begin{center}
+ \hspace*{-0.2in}\pgfimage[width=2.5in]{MEDIA/m2/mlab_tui}
+ \end{center}
+\end{frame}
- if score > 90:
- science[region_code] += 1
-
-pie(science.values(), labels=science.keys())
-savefig('science.png')
-\end{lstlisting}
-\inctime{10}
+\begin{frame}
+ {Exploring the documentation}
+ \begin{center}
+ \pgfimage[width=4in]{MEDIA/m2/m2_ug_doc}
+ \end{center}
\end{frame}
-%% \begin{frame}
-%% \frametitle{Testing}
-
-%% \begin{itemize}
-%% \item Writing tests is really simple!
-
-%% \item Using nose.
-
-%% \item Example!
-%% \end{itemize}
-%% \end{frame}
-\section{Test Driven Approach}
\begin{frame}
- \frametitle{Need for Testing!}
-
- \begin{itemize}
- \item Quality
- \item Regression
- \item Documentation
- \end{itemize}
- %% \vspace*{0.25in}
- %% \emphbar{It is to assure that section of code is working as it is supposed to work}
+ \frametitle{Summary}
+ \begin{itemize}
+ \item \url{http://code.enthought.com/projects/mayavi}
+ \item Uses VTK (\url{www.vtk.org})
+ \item BSD license
+ \item Linux, win32 and Mac OS X
+ \item Highly scriptable
+ \item Embed in Traits UIs (wxPython and PyQt4)
+ \item Envisage Plugins
+ \item Debian/Ubuntu/Fedora
+ \item \alert{Pythonic}
+ \end{itemize}
+
+ \inctime{10}
+
\end{frame}
-\begin{frame}[fragile]
- \frametitle{Example}
- \begin{block}{Problem Statement}
- Write a function to check whether a given input
- string is a palindrome.
- \end{block}
-\end{frame}
+\begin{frame}
+ {Getting hands dirty!}
-\begin{frame}[fragile]
- \frametitle{Function: palindrome.py}
-\begin{lstlisting}
-def is_palindrome(input_str):
- return input_str == input_str[::-1]
-\end{lstlisting}
+ \begin{block}{Motivational problem}
+ Atmospheric data of temperature over the surface of the earth.
+ Let temperature ($T$) vary linearly with height ($z$):
+ \begin{center}
+ $T = 288.15 - 6.5z$
+ \end{center}
+ \end{block}
\end{frame}
\begin{frame}[fragile]
- \frametitle{Test for the palindrome: palindrome.py}
-\begin{lstlisting}
-def test_function_normal_words():
- input = "noon"
- assert is_palindrome(input) == True
-
-if __name__ == "main'':
- test_function_normal_words()
-\end{lstlisting}
-\end{frame}
+ \frametitle{Simple solution}
-\begin{frame}[fragile]
- \frametitle{Running the tests.}
-\begin{lstlisting}
-$ nosetests palindrome.py
-.
-----------------------------------------------
-Ran 1 test in 0.001s
-
-OK
-\end{lstlisting}
+ \begin{lstlisting}
+lat = linspace(-89, 89, 37)
+lon = linspace(0, 360, 37)
+z = linspace(0, 100, 11)
+ \end{lstlisting}
+\pause
+ \begin{lstlisting}
+x, y, z = mgrid[0:360:37j,-89:89:37j,
+ 0:100:11j]
+t = 288.15 - 6.5*z
+mlab.contour3d(x, y, z, t)
+mlab.outline()
+mlab.colorbar()
+ \end{lstlisting}
\end{frame}
\begin{frame}[fragile]
- \frametitle{Exercise: Including new tests.}
-\begin{lstlisting}
-def test_function_ignore_cases_words():
- input = "Noon"
- assert is_palindrome(input) == True
-\end{lstlisting}
- \vspace*{0.25in}
- Check\\
- \PythonCode{$ nosetests palindrome.py} \\
- \begin{block}{Task}
- Tweak the code to pass this test.
- \end{block}
+ \frametitle{Exercise: Lorenz equation}
+ \begin{columns}
+ \column{0.25\textwidth}
+ \begin{eqnarray*}
+ \frac{d x}{dt} &=& s (y-x)\\
+ \frac{d y}{d t} &=& rx -y -xz\\
+ \frac{d z}{d t} &=& xy - bz\\
+ \end{eqnarray*}
+ \column{0.25\textwidth}
+ Let $s=10,$
+ $r=28,$
+ $b=8./3.$
+ \end{columns}
+ \structure{\Large Region of interest}
+ \begin{lstlisting}
+x, y, z = mgrid[-50:50:20j,-50:50:20j,
+ -10:60:20j]
+ \end{lstlisting}
+\inctime{20}
+
+\end{frame}
+\begin{frame}[fragile]
+ \frametitle{Solution}
+ \begin{lstlisting}
+def lorenz(x,y,z,s=10.,r=28.,b=8./3.):
+ u = s*(y-x)
+ v = r*x-y-x*z
+ w = x*y-b*z
+ return u,v,w
+x,y,z = mgrid [-50:50:20j,-50:50:20j,
+ -10:60:20j ]
+u,v,w = lorenz( x , y , z )
+# Your plot here
+#
+mlab.show()
+
+ \end{lstlisting}
\end{frame}
-%\begin{frame}[fragile]
-% \frametitle{Lets write some test!}
-%\begin{lstlisting}
-%#for form of equation y=mx+c
-%#given m and c for two equation,
-%#finding the intersection point.
-%def intersect(m1,c1,m2,c2):
-% x = (c2-c1)/(m1-m2)
-% y = m1*x+c1
-% return (x,y)
-%\end{lstlisting}
-%
-%Create a simple test for this
-%
-%function which will make it fail.
-%
-%\inctime{15}
-%\end{frame}
-%
-
-%% \begin{frame}[fragile]
-%% \frametitle{Exercise}
-%% Based on Euclid's algorithm:
-%% \begin{center}
-%% $gcd(a,b)=gcd(b,b\%a)$
-%% \end{center}
-%% gcd function can be written as:
-%% \begin{lstlisting}
-%% def gcd(a, b):
-%% if a%b == 0: return b
-%% return gcd(b, a%b)
-%% \end{lstlisting}
-%% \vspace*{-0.15in}
-%% \begin{block}{Task}
-%% \begin{itemize}
-%% \item Write at least
-%% two tests for above mentioned function.
-%% \item Write a non recursive implementation
-%% of gcd(), and test it using already
-%% written tests.
-%% \end{itemize}
-%% \end{block}
-
-%% \inctime{15}
-%% \end{frame}
-
\begin{frame}
- \frametitle{Summary}
-We have coverd:
+ \frametitle{We have covered:}
\begin{itemize}
- \item Following and Resolving Error Messages.
- \item Exceptions.
- \item Handling exceptions
- \item Approach for Debugging.
- \item Writting and running tests.
+ \item Need of visualization.
+ \item Using mlab to create 3 D plots.
+ \item Mayavi Toolkit.
\end{itemize}
\end{frame}
\end{document}
+
--- a/day2/session5.tex Fri Nov 06 17:56:22 2009 +0530
+++ b/day2/session5.tex Fri Nov 06 18:33:08 2009 +0530
@@ -1,33 +1,48 @@
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-%Tutorial slides on Python.
+% Tutorial slides on Python.
%
% Author: Prabhu Ramachandran <prabhu at aero.iitb.ac.in>
% Copyright (c) 2005-2009, Prabhu Ramachandran
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\documentclass[14pt,compress]{beamer}
-%\documentclass[draft]{beamer}
-%\documentclass[compress,handout]{beamer}
-%\usepackage{pgfpages}
-%\pgfpagesuselayout{2 on 1}[a4paper,border shrink=5mm]
+\documentclass[compress,14pt]{beamer}
+% \documentclass[handout]{beamer}
+% \usepackage{pgfpages}
+% \pgfpagesuselayout{4 on 1}[a4paper,border, shrink=5mm,landscape]
+\usepackage{tikz}
+\newcommand{\hyperlinkmovie}{}
+%\usepackage{movie15}
-% Modified from: generic-ornate-15min-45min.de.tex
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Note that in presentation mode
+% \paperwidth 364.19536pt
+% \paperheight 273.14662pt
+% h/w = 0.888
+
+
\mode<presentation>
{
\usetheme{Warsaw}
+ %\usetheme{Boadilla}
+ %\usetheme{default}
\useoutertheme{infolines}
\setbeamercovered{transparent}
}
+% To remove navigation symbols
+\setbeamertemplate{navigation symbols}{}
+
+\usepackage{amsmath}
\usepackage[english]{babel}
\usepackage[latin1]{inputenc}
-%\usepackage{times}
+\usepackage{times}
\usepackage[T1]{fontenc}
% Taken from Fernando's slides.
\usepackage{ae,aecompl}
\usepackage{mathpazo,courier,euler}
\usepackage[scaled=.95]{helvet}
+\usepackage{pgf}
\definecolor{darkgreen}{rgb}{0,0.5,0}
@@ -40,50 +55,65 @@
keywordstyle=\color{blue}\bfseries}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-% Macros
+% My Macros
+\setbeamercolor{postit}{bg=yellow,fg=black}
\setbeamercolor{emphbar}{bg=blue!20, fg=black}
\newcommand{\emphbar}[1]
{\begin{beamercolorbox}[rounded=true]{emphbar}
{#1}
\end{beamercolorbox}
}
+%{\centerline{\fcolorbox{gray!50} {blue!10}{
+%\begin{minipage}{0.9\linewidth}
+% {#1}
+%\end{minipage}
+% }}}
+
+\newcommand{\myemph}[1]{\structure{\emph{#1}}}
+\newcommand{\PythonCode}[1]{\lstinline{#1}}
+
+\newcommand{\tvtk}{\texttt{tvtk}}
+\newcommand{\mlab}{\texttt{mlab}}
+\newcommand{\typ}[1]{\lstinline{#1}}
\newcounter{time}
\setcounter{time}{0}
-\newcommand{\inctime}[1]{\addtocounter{time}{#1}{\tiny \thetime\ m}}
-
-\newcommand{\typ}[1]{\texttt{#1}}
-
-\newcommand{\kwrd}[1]{ \texttt{\textbf{\color{blue}{#1}}} }
+\newcommand{\inctime}[1]{\addtocounter{time}{#1}{\vspace*{0.1in}\tiny \thetime\ m}}
-%%% This is from Fernando's setup.
-% \usepackage{color}
-% \definecolor{orange}{cmyk}{0,0.4,0.8,0.2}
-% % Use and configure listings package for nicely formatted code
-% \usepackage{listings}
-% \lstset{
-% language=Python,
-% basicstyle=\small\ttfamily,
-% commentstyle=\ttfamily\color{blue},
-% stringstyle=\ttfamily\color{orange},
-% showstringspaces=false,
-% breaklines=true,
-% postbreak = \space\dots
-% }
+\newcommand\BackgroundPicture[1]{%
+ \setbeamertemplate{background}{%
+ \parbox[c][\paperheight]{\paperwidth}{%
+ \vfill \hfill
+ \hfill \vfill
+}}}
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Configuring the theme
+%\setbeamercolor{normal text}{fg=white}
+%\setbeamercolor{background canvas}{bg=black}
+
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Title page
-\title[Exercises]{Exercises}
+\title[Python Development]{Python Development}
\author[FOSSEE] {FOSSEE}
\institute[IIT Bombay] {Department of Aerospace Engineering\\IIT Bombay}
-\date[] {1 November, 2009\\Day 2, Session 4}
+\date[] {1 November, 2009\\Day 2, Session 3}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-%\pgfdeclareimage[height=0.75cm]{iitmlogo}{iitmlogo}
-%\logo{\pgfuseimage{iitmlogo}}
+%\pgfdeclareimage[height=0.75cm]{iitblogo}{iitblogo}
+%\logo{\pgfuseimage{iitblogo}}
+\AtBeginSection[]
+{
+ \begin{frame}<beamer>
+ \frametitle{Outline}
+ \Large
+ \tableofcontents[currentsection,currentsubsection]
+ \end{frame}
+}
%% Delete this, if you do not want the table of contents to pop up at
%% the beginning of each subsection:
@@ -95,109 +125,438 @@
\end{frame}
}
-
-% If you wish to uncover everything in a step-wise fashion, uncomment
-% the following command:
-%\beamerdefaultoverlayspecification{<+->}
-
-%\includeonlyframes{current,current1,current2,current3,current4,current5,current6}
-
+\AtBeginSection[]
+{
+ \begin{frame}<beamer>
+ \frametitle{Outline}
+ \tableofcontents[currentsection,currentsubsection]
+ \end{frame}
+}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% DOCUMENT STARTS
\begin{document}
\begin{frame}
- \titlepage
+ \maketitle
+\end{frame}
+
+\section{Tests: Getting started}
+\begin{frame}[fragile]
+ \frametitle{gcd revisited!}
+ \begin{itemize}
+ \item Open gcd.py
+ \end{itemize}
+\begin{lstlisting}
+ def gcd(a, b):
+ if a % b == 0:
+ return b
+ return gcd(b, a%b)
+
+ print gcd(15, 65)
+ print gcd(16, 76)
+\end{lstlisting}
+ \begin{itemize}
+ \item python gcd.py
+ \end{itemize}
\end{frame}
-\begin{frame}{Problem 1.1}
- The aliquot of a number is defined as: the sum of the \emph{proper} divisors of the number. \\For example:
-\center{aliquot(12) = 1 + 2 + 3 + 4 + 6 = 16.}\\
- Write a function that returns the aliquot number of a given number.
+\begin{frame}[fragile]
+ \frametitle{Find lcm using our gcd module}
+ \begin{itemize}
+ \item Open lcm.py
+ \item $lcm = \frac{a*b}{gcd(a,b)}$
+ \end{itemize}
+\begin{lstlisting}
+ from gcd import gcd
+ def lcm(a, b):
+ return (a * b) / gcd(a, b)
+
+ print lcm(14, 56)
+\end{lstlisting}
+ \begin{itemize}
+ \item python lcm.py
+ \end{itemize}
+ \begin{lstlisting}
+5
+4
+56
+ \end{lstlisting}
\end{frame}
-\begin{frame}{Problem 1.2}
- Pair of numbers (a, b) is said to be \alert{amicable} if aliquot number of a is b and aliquot number of b is a.\\
- Example: \texttt{220, 284}\\
- Write a program that prints all four digit amicable pairs.
-
-\inctime{20}
+\begin{frame}[fragile]
+ \frametitle{Writing stand-alone module}
+Edit gcd.py file to:
+\begin{lstlisting}
+ def gcd(a, b):
+ if a % b == 0:
+ return b
+ return gcd(b, a%b)
+
+ if __name__ == "__main__":
+ print gcd(15, 65)
+ print gcd(16, 76)
+\end{lstlisting}
+ \begin{itemize}
+ \item python gcd.py
+ \item python lcm.py
+ \end{itemize}
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{More use of main}
+ For automating tests.
+ \begin{lstlisting}
+if __name__ == '__main__':
+ for line in open('numbers.txt'):
+ numbers = line.split()
+ x = int(numbers[0])
+ y = int(numbers[1])
+ result = (int(numbers[2]))
+ assert gcd(x, y) == result
+ \end{lstlisting}
+\end{frame}
+
+\section{Coding Style}
+\begin{frame}{Readability and Consistency}
+ \begin{itemize}
+ \item Readability Counts!\\Code is read more often than its written.
+ \item Consistency!
+ \item Know when to be inconsistent.
+ \end{itemize}
\end{frame}
-%% \begin{frame}{Problem 2}
-%% Given an empty chessboard and one Bishop placed in any s%quare, say (r, c), generate the list of all squares the Bi%shop could move to.
-
-%% \end{frame}
+\begin{frame}[fragile] \frametitle{A question of good style}
+ \begin{lstlisting}
+ amount = 12.68
+ denom = 0.05
+ nCoins = round(amount/denom)
+ rAmount = nCoins * denom
+ \end{lstlisting}
+ \pause
+ \begin{block}{Style Rule \#1}
+ Naming is 80\% of programming
+ \end{block}
+\end{frame}
\begin{frame}[fragile]
- \frametitle{Problem Set 2}
- Given a string like, ``1, 3-7, 12, 15, 18-21'', produce the list \\
- \begin{lstlisting}
- [1,3,4,5,6,7,12,15,18,19,20,21]
- \end{lstlisting}
-\inctime{10}
+ \frametitle{Code Layout}
+ \begin{itemize}
+ \item Indentation
+ \item Tabs or Spaces??
+ \item Maximum Line Length
+ \item Blank Lines
+ \item Encodings
+ \end{itemize}
+\end{frame}
+
+\begin{frame}{Whitespaces in Expressions}
+ \begin{itemize}
+ \item When to use extraneous whitespaces??
+ \item When to avoid extra whitespaces??
+ \item Use one statement per line
+ \end{itemize}
+\end{frame}
+
+\begin{frame}{Comments}
+ \begin{itemize}
+ \item No comments better than contradicting comments
+ \item Block comments
+ \item Inline comments
+ \end{itemize}
+\end{frame}
+
+\begin{frame}{Docstrings}
+ \begin{itemize}
+ \item When to write docstrings?
+ \item Ending the docstrings
+ \item One liner docstrings
+ \end{itemize}
+More information at PEP8: http://www.python.org/dev/peps/pep-0008/
+\inctime{5}
\end{frame}
-\begin{frame}
- \frametitle{Problem Set 3}
- \begin{description}
- \item[3.1] Count word frequencies in a file.
-\end{description}
-\inctime{5}
+\section{Debugging}
+\subsection{Errors and Exceptions}
+\begin{frame}[fragile]
+ \frametitle{Errors}
+ \begin{lstlisting}
+In []: while True print 'Hello world'
+ \end{lstlisting}
+\pause
+ \begin{lstlisting}
+ File "<stdin>", line 1, in ?
+ while True print 'Hello world'
+ ^
+SyntaxError: invalid syntax
+\end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{Exceptions}
+ \begin{lstlisting}
+In []: print spam
+\end{lstlisting}
+\pause
+\begin{lstlisting}
+Traceback (most recent call last):
+ File "<stdin>", line 1, in <module>
+NameError: name 'spam' is not defined
+\end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{Exceptions}
+ \begin{lstlisting}
+In []: 1 / 0
+\end{lstlisting}
+\pause
+\begin{lstlisting}
+Traceback (most recent call last):
+ File "<stdin>", line 1, in <module>
+ZeroDivisionError: integer division
+or modulo by zero
+\end{lstlisting}
\end{frame}
\begin{frame}[fragile]
- \frametitle{Problem set 4}
- Central difference
- \begin{equation*}
- \frac{sin(x+h)-sin(x-h)}{2h}
- \end{equation*}
+ \frametitle{Handling Exceptions}
+ Python uses \typ{try} and \typ{except} clause.
+ %%Revisiting the raw\_input
\begin{lstlisting}
- In []: x = linspace(0, 2*pi, 100)
- In []: y = sin(x)
- In []: deltax = x[1] - x[0]
+a = raw_input('Enter number(Q to quit):')
+try:
+ num = int(a)
+ print num
+except:
+ if a == 'Q':
+ print 'Exiting...'
+ else:
+ print 'Wrong input!'
\end{lstlisting}
- \pause
- \begin{enumerate}
- \item Given this, get the finite difference of sin in the range 0 to 2*pi
- \end{enumerate}
+
+
+\end{frame}
+
+%% \begin{frame}[fragile]
+%% \frametitle{Solving it with \typ{try} and \typ{except}}
+%% \vspace{-0.2in}
+%% \begin{lstlisting}
+%% highest = 0
+%% for record in open('sslc1.txt'):
+%% fields = record.split(';')
+%% try:
+%% total = 0
+%% for score_str in fields[3:8]:
+%% score = int(score_str)
+%% total += score
+%% if total > highest:
+%% highest = total
+%% except:
+%% pass
+%% print highest
+%% \end{lstlisting}
+%% \end{frame}
+\subsection{Strategy}
+\begin{frame}[fragile]
+ \frametitle{Debugging effectively}
+ \begin{itemize}
+ \item \typ{print} based strategy
+ \item Process:
+ \end{itemize}
+\begin{center}
+\pgfimage[interpolate=true,width=5cm,height=5cm]{DebugginDiagram.png}
+\end{center}
\end{frame}
-\begin{frame}
- \frametitle{Problem Set 5}
- \begin{itemize}
- \item[5.1] Write a function that plots any regular n-gon given \typ{n}.
- \item[5.2] Consider the logistic map, $f(x) = kx(1-x)$, plot it for
- $k=2.5, 3.5$ and $4$ in the same plot.
-\end{itemize}
+\begin{frame}[fragile]
+ \frametitle{Debugging effectively}
+ \begin{itemize}
+ \item Using \typ{\%debug} in IPython
+ \end{itemize}
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{Debugging in IPython}
+\small
+\begin{lstlisting}
+In []: import mymodule
+In []: mymodule.test()
+---------------------------------------------
+NameError Traceback (most recent call last)
+<ipython console> in <module>()
+mymodule.py in test()
+ 1 def test():
+----> 2 print spam
+NameError: global name 'spam' is not defined
+
+In []: %debug
+> mymodule.py(2)test()
+ 0 print spam
+ipdb>
+\end{lstlisting}
+\inctime{15}
+\end{frame}
+
+\subsection{Exercise}
+\begin{frame}[fragile]
+\frametitle{Debugging: Exercise}
+\small
+\begin{lstlisting}
+science = {}
+
+for record in open('sslc1.txt'):
+ fields = record.split(';')
+ region_code = fields[0].strip()
+
+ score_str = fields[6].strip()
+ score = int(score_str) if score_str != 'AA'
+ else 0
+
+ if score > 90:
+ science[region_code] += 1
+
+pie(science.values(), labels=science.keys())
+savefig('science.png')
+\end{lstlisting}
+\inctime{10}
\end{frame}
-\begin{frame}[fragile]
-\frametitle{Problem Set 5}
- \begin{columns}
- \column{0.6\textwidth}
- \small{
+%% \begin{frame}
+%% \frametitle{Testing}
+
+%% \begin{itemize}
+%% \item Writing tests is really simple!
+
+%% \item Using nose.
+
+%% \item Example!
+%% \end{itemize}
+%% \end{frame}
+
+\section{Test Driven Approach}
+\begin{frame}
+ \frametitle{Need for Testing!}
+
\begin{itemize}
- \item[3] Consider the iteration $x_{n+1} = f(x_n)$ where $f(x) = kx(1-x)$. Plot the successive iterates of this process as explained below.
- \end{itemize}}
- \column{0.35\textwidth}
- \hspace*{-0.5in}
- \includegraphics[height=1.6in, interpolate=true]{data/cobweb}
-\end{columns}
+ \item Quality
+ \item Regression
+ \item Documentation
+ \end{itemize}
+ %% \vspace*{0.25in}
+ %% \emphbar{It is to assure that section of code is working as it is supposed to work}
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{Example}
+ \begin{block}{Problem Statement}
+ Write a function to check whether a given input
+ string is a palindrome.
+ \end{block}
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{Function: palindrome.py}
+\begin{lstlisting}
+def is_palindrome(input_str):
+ return input_str == input_str[::-1]
+\end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{Test for the palindrome: palindrome.py}
+\begin{lstlisting}
+def test_function_normal_words():
+ input = "noon"
+ assert is_palindrome(input) == True
+
+if __name__ == "main'':
+ test_function_normal_words()
+\end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{Running the tests.}
+\begin{lstlisting}
+$ nosetests palindrome.py
+.
+----------------------------------------------
+Ran 1 test in 0.001s
+
+OK
+\end{lstlisting}
\end{frame}
+\begin{frame}[fragile]
+ \frametitle{Exercise: Including new tests.}
+\begin{lstlisting}
+def test_function_ignore_cases_words():
+ input = "Noon"
+ assert is_palindrome(input) == True
+\end{lstlisting}
+ \vspace*{0.25in}
+ Check\\
+ \PythonCode{$ nosetests palindrome.py} \\
+ \begin{block}{Task}
+ Tweak the code to pass this test.
+ \end{block}
+\end{frame}
+
+%\begin{frame}[fragile]
+% \frametitle{Lets write some test!}
+%\begin{lstlisting}
+%#for form of equation y=mx+c
+%#given m and c for two equation,
+%#finding the intersection point.
+%def intersect(m1,c1,m2,c2):
+% x = (c2-c1)/(m1-m2)
+% y = m1*x+c1
+% return (x,y)
+%\end{lstlisting}
+%
+%Create a simple test for this
+%
+%function which will make it fail.
+%
+%\inctime{15}
+%\end{frame}
+%
+
+%% \begin{frame}[fragile]
+%% \frametitle{Exercise}
+%% Based on Euclid's algorithm:
+%% \begin{center}
+%% $gcd(a,b)=gcd(b,b\%a)$
+%% \end{center}
+%% gcd function can be written as:
+%% \begin{lstlisting}
+%% def gcd(a, b):
+%% if a%b == 0: return b
+%% return gcd(b, a%b)
+%% \end{lstlisting}
+%% \vspace*{-0.15in}
+%% \begin{block}{Task}
+%% \begin{itemize}
+%% \item Write at least
+%% two tests for above mentioned function.
+%% \item Write a non recursive implementation
+%% of gcd(), and test it using already
+%% written tests.
+%% \end{itemize}
+%% \end{block}
+
+%% \inctime{15}
+%% \end{frame}
+
\begin{frame}
- \frametitle{Problem Set 5.3}
- Plot the cobweb plot as follows:
- \begin{enumerate}
- \item Start at $(x_0, 0)$ ($\implies$ i=0)
- \item Draw a line to $(x_i, f(x_i))$
- \item Set $x_{i+1} = f(x_i)$
- \item Draw a line to $(x_{i+1}, x_{i+1})$
- \item $(i\implies i+1)$
- \item Repeat from 2 for as long as you want
- \end{enumerate}
-\inctime{20}
+ \frametitle{Summary}
+We have coverd:
+ \begin{itemize}
+ \item Following and Resolving Error Messages.
+ \item Exceptions.
+ \item Handling exceptions
+ \item Approach for Debugging.
+ \item Writting and running tests.
+ \end{itemize}
\end{frame}
\end{document}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/day2/session6.tex Fri Nov 06 18:33:08 2009 +0530
@@ -0,0 +1,203 @@
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%Tutorial slides on Python.
+%
+% Author: Prabhu Ramachandran <prabhu at aero.iitb.ac.in>
+% Copyright (c) 2005-2009, Prabhu Ramachandran
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+\documentclass[14pt,compress]{beamer}
+%\documentclass[draft]{beamer}
+%\documentclass[compress,handout]{beamer}
+%\usepackage{pgfpages}
+%\pgfpagesuselayout{2 on 1}[a4paper,border shrink=5mm]
+
+% Modified from: generic-ornate-15min-45min.de.tex
+\mode<presentation>
+{
+ \usetheme{Warsaw}
+ \useoutertheme{infolines}
+ \setbeamercovered{transparent}
+}
+
+\usepackage[english]{babel}
+\usepackage[latin1]{inputenc}
+%\usepackage{times}
+\usepackage[T1]{fontenc}
+
+% Taken from Fernando's slides.
+\usepackage{ae,aecompl}
+\usepackage{mathpazo,courier,euler}
+\usepackage[scaled=.95]{helvet}
+
+\definecolor{darkgreen}{rgb}{0,0.5,0}
+
+\usepackage{listings}
+\lstset{language=Python,
+ basicstyle=\ttfamily\bfseries,
+ commentstyle=\color{red}\itshape,
+ stringstyle=\color{darkgreen},
+ showstringspaces=false,
+ keywordstyle=\color{blue}\bfseries}
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Macros
+\setbeamercolor{emphbar}{bg=blue!20, fg=black}
+\newcommand{\emphbar}[1]
+{\begin{beamercolorbox}[rounded=true]{emphbar}
+ {#1}
+ \end{beamercolorbox}
+}
+\newcounter{time}
+\setcounter{time}{0}
+\newcommand{\inctime}[1]{\addtocounter{time}{#1}{\tiny \thetime\ m}}
+
+\newcommand{\typ}[1]{\texttt{#1}}
+
+\newcommand{\kwrd}[1]{ \texttt{\textbf{\color{blue}{#1}}} }
+
+%%% This is from Fernando's setup.
+% \usepackage{color}
+% \definecolor{orange}{cmyk}{0,0.4,0.8,0.2}
+% % Use and configure listings package for nicely formatted code
+% \usepackage{listings}
+% \lstset{
+% language=Python,
+% basicstyle=\small\ttfamily,
+% commentstyle=\ttfamily\color{blue},
+% stringstyle=\ttfamily\color{orange},
+% showstringspaces=false,
+% breaklines=true,
+% postbreak = \space\dots
+% }
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Title page
+\title[Exercises]{Exercises}
+
+\author[FOSSEE] {FOSSEE}
+
+\institute[IIT Bombay] {Department of Aerospace Engineering\\IIT Bombay}
+\date[] {1 November, 2009\\Day 2, Session 4}
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%\pgfdeclareimage[height=0.75cm]{iitmlogo}{iitmlogo}
+%\logo{\pgfuseimage{iitmlogo}}
+
+
+%% Delete this, if you do not want the table of contents to pop up at
+%% the beginning of each subsection:
+\AtBeginSubsection[]
+{
+ \begin{frame}<beamer>
+ \frametitle{Outline}
+ \tableofcontents[currentsection,currentsubsection]
+ \end{frame}
+}
+
+
+% If you wish to uncover everything in a step-wise fashion, uncomment
+% the following command:
+%\beamerdefaultoverlayspecification{<+->}
+
+%\includeonlyframes{current,current1,current2,current3,current4,current5,current6}
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% DOCUMENT STARTS
+\begin{document}
+
+\begin{frame}
+ \titlepage
+\end{frame}
+
+\begin{frame}{Problem 1.1}
+ The aliquot of a number is defined as: the sum of the \emph{proper} divisors of the number. \\For example:
+\center{aliquot(12) = 1 + 2 + 3 + 4 + 6 = 16.}\\
+ Write a function that returns the aliquot number of a given number.
+\end{frame}
+
+\begin{frame}{Problem 1.2}
+ Pair of numbers (a, b) is said to be \alert{amicable} if aliquot number of a is b and aliquot number of b is a.\\
+ Example: \texttt{220, 284}\\
+ Write a program that prints all four digit amicable pairs.
+
+\inctime{20}
+\end{frame}
+
+%% \begin{frame}{Problem 2}
+%% Given an empty chessboard and one Bishop placed in any s%quare, say (r, c), generate the list of all squares the Bi%shop could move to.
+
+%% \end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{Problem Set 2}
+ Given a string like, ``1, 3-7, 12, 15, 18-21'', produce the list \\
+ \begin{lstlisting}
+ [1,3,4,5,6,7,12,15,18,19,20,21]
+ \end{lstlisting}
+\inctime{10}
+\end{frame}
+
+\begin{frame}
+ \frametitle{Problem Set 3}
+ \begin{description}
+ \item[3.1] Count word frequencies in a file.
+\end{description}
+\inctime{5}
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{Problem set 4}
+ Central difference
+ \begin{equation*}
+ \frac{sin(x+h)-sin(x-h)}{2h}
+ \end{equation*}
+ \begin{lstlisting}
+ In []: x = linspace(0, 2*pi, 100)
+ In []: y = sin(x)
+ In []: deltax = x[1] - x[0]
+ \end{lstlisting}
+ \pause
+ \begin{enumerate}
+ \item Given this, get the finite difference of sin in the range 0 to 2*pi
+ \end{enumerate}
+\end{frame}
+
+\begin{frame}
+ \frametitle{Problem Set 5}
+ \begin{itemize}
+ \item[5.1] Write a function that plots any regular n-gon given \typ{n}.
+ \item[5.2] Consider the logistic map, $f(x) = kx(1-x)$, plot it for
+ $k=2.5, 3.5$ and $4$ in the same plot.
+\end{itemize}
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{Problem Set 5}
+ \begin{columns}
+ \column{0.6\textwidth}
+ \small{
+ \begin{itemize}
+ \item[3] Consider the iteration $x_{n+1} = f(x_n)$ where $f(x) = kx(1-x)$. Plot the successive iterates of this process as explained below.
+ \end{itemize}}
+ \column{0.35\textwidth}
+ \hspace*{-0.5in}
+ \includegraphics[height=1.6in, interpolate=true]{data/cobweb}
+\end{columns}
+\end{frame}
+
+\begin{frame}
+ \frametitle{Problem Set 5.3}
+ Plot the cobweb plot as follows:
+ \begin{enumerate}
+ \item Start at $(x_0, 0)$ ($\implies$ i=0)
+ \item Draw a line to $(x_i, f(x_i))$
+ \item Set $x_{i+1} = f(x_i)$
+ \item Draw a line to $(x_{i+1}, x_{i+1})$
+ \item $(i\implies i+1)$
+ \item Repeat from 2 for as long as you want
+ \end{enumerate}
+\inctime{20}
+\end{frame}
+
+\end{document}