# HG changeset patch # User Madhusudan.C.S # Date 1257512802 -19800 # Node ID 884d42eff66d5582f0c034941b9b0df947825f67 # Parent c4e25269a86c2790bdcbac123ada67c1edbf6676 Reorganized last 3 sessions of day 2 again. diff -r c4e25269a86c -r 884d42eff66d day2/session4.tex --- a/day2/session4.tex Fri Nov 06 18:33:08 2009 +0530 +++ b/day2/session4.tex Fri Nov 06 18:36:42 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}} @@ -95,13 +95,12 @@ %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % Title page -\title[3D Plotting]{3D data Visualization} +\title[Python Development]{Python Development} \author[FOSSEE] {FOSSEE} \institute[IIT Bombay] {Department of Aerospace Engineering\\IIT Bombay} -\date[] {1 November, 2009\\Day 2, Session 5} - +\date[] {8 November, 2009\\Day 2, Session 4} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %\pgfdeclareimage[height=0.75cm]{iitblogo}{iitblogo} @@ -110,7 +109,8 @@ \AtBeginSection[] { \begin{frame} - \frametitle{Outline} + \frametitle{Outline} + \Large \tableofcontents[currentsection,currentsubsection] \end{frame} } @@ -140,419 +140,423 @@ \maketitle \end{frame} -\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} - +\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{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} + print gcd(15, 65) + print gcd(16, 76) +\end{lstlisting} + \begin{itemize} + \item python gcd.py + \end{itemize} \end{frame} -\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} +\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} -\section{Tools available} - -\subsection{mlab} +\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) -\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} + 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{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_ -In []: mlab.test_contour3d() -In []: mlab.test_contour3d?? - \end{lstlisting} + \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} -\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} +\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{\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} + \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{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)}} +\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} - \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}{Comments} + \begin{itemize} + \item No comments better than contradicting comments + \item Block comments + \item Inline comments + \end{itemize} +\end{frame} - Plots lines between the points - +\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 "", line 1, in ? + while True print 'Hello world' + ^ +SyntaxError: invalid syntax +\end{lstlisting} \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} - + \frametitle{Exceptions} + \begin{lstlisting} +In []: print spam +\end{lstlisting} +\pause +\begin{lstlisting} +Traceback (most recent call last): + File "", line 1, in +NameError: name 'spam' is not defined +\end{lstlisting} \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]]]) - -In []: mgrid[-1:1:5j] -Out[]: array([-1., -0.5, 0., 0.5, 1.]) + \frametitle{Exceptions} + \begin{lstlisting} +In []: 1 / 0 +\end{lstlisting} +\pause +\begin{lstlisting} +Traceback (most recent call last): + File "", line 1, in +ZeroDivisionError: integer division +or modulo by zero \end{lstlisting} \end{frame} \begin{frame}[fragile] - \frametitle{Example} + \frametitle{Handling Exceptions} + Python uses \typ{try} and \typ{except} clause. + %%Revisiting the raw\_input \begin{lstlisting} -In []: x, y = mgrid[-1:1:5j, -1:1:5j] -In []: z = x*x + y*y +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 []: 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} +%% \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}[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} - -\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} + \frametitle{Debugging effectively} + \begin{itemize} + \item Using \typ{\%debug} in IPython + \end{itemize} \end{frame} \begin{frame}[fragile] - - \myemph{\Large 3D vector data: \PythonCode{mlab.quiver3d}} - \vspace*{0.25in} +\frametitle{Debugging in IPython} +\small +\begin{lstlisting} +In []: import mymodule +In []: mymodule.test() +--------------------------------------------- +NameError Traceback (most recent call last) + in () +mymodule.py in test() + 1 def test(): +----> 2 print spam +NameError: global name 'spam' is not defined - \pgfimage[width=2in]{MEDIA/m2/mlab/quiver3d_ex}\\ - -\begin{lstlisting} -In []: mlab.test_quiver3d() +In []: %debug +> mymodule.py(2)test() + 0 print spam +ipdb> \end{lstlisting} - -\emphbar{\PythonCode{obj = mlab.quiver3d(x, y, z, u, v, w)}} -\inctime{20} +\inctime{15} \end{frame} +\subsection{Exercise} +\begin{frame}[fragile] +\frametitle{Debugging: Exercise} +\small +\begin{lstlisting} +science = {} -\subsection{Mayavi2} +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} +%% \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{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} + \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} +\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} - {Overview of features} - \vspace*{-0.3in} - \begin{center} - \hspace*{-0.2in}\pgfimage[width=5in]{MEDIA/m2/m2_app3_3} - \end{center} +\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} - \frametitle{Mayavi in applications} - \vspace*{-0.3in} - \begin{center} - \hspace*{-0.2in}\pgfimage[width=4.5in]{MEDIA/m2/m2_envisage} - \end{center} +\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} - \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}[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} - {Exploring the documentation} - \begin{center} - \pgfimage[width=4in]{MEDIA/m2/m2_ug_doc} - \end{center} -\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} - \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() - - \end{lstlisting} -\end{frame} - -\begin{frame} - \frametitle{We have covered:} +We have coverd: \begin{itemize} - \item Need of visualization. - \item Using mlab to create 3 D plots. - \item Mayavi Toolkit. + \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} - diff -r c4e25269a86c -r 884d42eff66d day2/session5.tex --- a/day2/session5.tex Fri Nov 06 18:33:08 2009 +0530 +++ b/day2/session5.tex Fri Nov 06 18:36:42 2009 +0530 @@ -1,48 +1,33 @@ %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -% Tutorial slides on Python. +%Tutorial slides on Python. % % Author: Prabhu Ramachandran % Copyright (c) 2005-2009, Prabhu Ramachandran %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\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 { \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}} -\newcommand{\typ}[1]{\lstinline{#1}} \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[Python Development]{Python Development} +\title[Exercises]{Exercises} \author[FOSSEE] {FOSSEE} \institute[IIT Bombay] {Department of Aerospace Engineering\\IIT Bombay} -\date[] {1 November, 2009\\Day 2, Session 3} +\date[] {8 November, 2009\\Day 2, Session 5} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -%\pgfdeclareimage[height=0.75cm]{iitblogo}{iitblogo} -%\logo{\pgfuseimage{iitblogo}} +%\pgfdeclareimage[height=0.75cm]{iitmlogo}{iitmlogo} +%\logo{\pgfuseimage{iitmlogo}} -\AtBeginSection[] -{ - \begin{frame} - \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: @@ -125,438 +95,109 @@ \end{frame} } -\AtBeginSection[] -{ - \begin{frame} - \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} - \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} + \titlepage \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}{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}[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} +\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}[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}{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{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} + \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}{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/ +\begin{frame} + \frametitle{Problem Set 3} + \begin{description} + \item[3.1] Count word frequencies in a file. +\end{description} \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 "", 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 "", line 1, in -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 "", line 1, in -ZeroDivisionError: integer division -or modulo by zero -\end{lstlisting} -\end{frame} - \begin{frame}[fragile] - \frametitle{Handling Exceptions} - Python uses \typ{try} and \typ{except} clause. - %%Revisiting the raw\_input + \frametitle{Problem set 4} + Central difference + \begin{equation*} + \frac{sin(x+h)-sin(x-h)}{2h} + \end{equation*} \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!' + In []: x = linspace(0, 2*pi, 100) + In []: y = sin(x) + In []: deltax = x[1] - x[0] \end{lstlisting} - - -\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} + \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{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) - in () -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} +\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} -%% \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{frame}[fragile] +\frametitle{Problem Set 5} + \begin{columns} + \column{0.6\textwidth} + \small{ \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} -\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} + \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}[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{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} + \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} diff -r c4e25269a86c -r 884d42eff66d day2/session6.tex --- a/day2/session6.tex Fri Nov 06 18:33:08 2009 +0530 +++ b/day2/session6.tex Fri Nov 06 18:36:42 2009 +0530 @@ -1,33 +1,48 @@ %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -%Tutorial slides on Python. +% Tutorial slides on Python. % % Author: Prabhu Ramachandran % 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 { \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}} + \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[3D Plotting]{3D data Visualization} \author[FOSSEE] {FOSSEE} \institute[IIT Bombay] {Department of Aerospace Engineering\\IIT Bombay} -\date[] {1 November, 2009\\Day 2, Session 4} +\date[] {8 November, 2009\\Day 2, Session 6} + %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -%\pgfdeclareimage[height=0.75cm]{iitmlogo}{iitmlogo} -%\logo{\pgfuseimage{iitmlogo}} +%\pgfdeclareimage[height=0.75cm]{iitblogo}{iitblogo} +%\logo{\pgfuseimage{iitblogo}} +\AtBeginSection[] +{ + \begin{frame} + \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: @@ -95,109 +125,434 @@ \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} + \frametitle{Outline} + \tableofcontents[currentsection,currentsubsection] + \end{frame} +} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % DOCUMENT STARTS \begin{document} \begin{frame} - \titlepage + \maketitle +\end{frame} + +\begin{frame} + \frametitle{Outline} + \tableofcontents + % You might wish to add the option [pausesections] \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. +\section{3D Data Visualization} + +\begin{frame} + \frametitle{What is visualization?} + \Large + \begin{center} + Visual representation of data + \end{center} \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} +%% \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}{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} + \frametitle{Is this Graphics?} + \Large + \begin{center} + Visualization is about data! + \end{center} +\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} +\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} - \frametitle{Problem Set 3} - \begin{description} - \item[3.1] Count word frequencies in a file. -\end{description} -\inctime{5} +\section{Tools available} + +\subsection{mlab} + +\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{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_ +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)}} + + 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]]]) + +In []: mgrid[-1:1:5j] +Out[]: array([-1., -0.5, 0., 0.5, 1.]) +\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{Example} \begin{lstlisting} - In []: x = linspace(0, 2*pi, 100) - In []: y = sin(x) - In []: deltax = x[1] - x[0] - \end{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} + +\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] + + \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{enumerate} - \item Given this, get the finite difference of sin in the range 0 to 2*pi - \end{enumerate} + \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{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} + \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} -\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} + +\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} - \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} + {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() + + \end{lstlisting} +\end{frame} + +\begin{frame} + \frametitle{We have covered:} + \begin{itemize} + \item Need of visualization. + \item Using mlab to create 3 D plots. + \item Mayavi Toolkit. + \end{itemize} \end{frame} \end{document} +