\documentclass[12pt]{article}

\title{Plotting Points}

\author{FOSSEE}

\usepackage{listings}

\lstset{language=Python,

    basicstyle=\ttfamily,

  commentstyle=\itshape\bfseries,

  showstringspaces=false,

}

\newcommand{\typ}[1]{\lstinline{#1}}

\usepackage[english]{babel}

\usepackage[latin1]{inputenc}

\usepackage{times}

\usepackage[T1]{fontenc}

\usepackage{ae,aecompl}

\usepackage{mathpazo,courier,euler}

\usepackage[scaled=.95]{helvet}

\begin{document}

\date{}

\vspace{-1in}

\begin{center}

\LARGE{Plotting Points}\\

\large{FOSSEE}

\end{center}

\section{Plotting Points with Lists}

\begin{lstlisting}

In []: x = [0, 1, 2, 3] # Creating a list

In []: y = [7, 11, 15, 19]

In []: plot(x, y)

In []: clf()

In []: plot(x, y, 'o')  # Plotting Circles

\end{lstlisting}

\subsection{Line style/marker}

\begin{lstlisting}

The following format string characters are accepted 

to control the line style or marker:

    ================    ===============================

    character           description

    ================    ===============================

    '-'                 solid line style

    '--'                dashed line style

    '-.'                dash-dot line style

    ':'                 dotted line style

    '.'                 point marker

    ','                 pixel marker

    'o'                 circle marker

    'v'                 triangle_down marker

    '^'                 triangle_up marker

    '<'                 triangle_left marker

    '>'                 triangle_right marker

    '1'                 tri_down marker

    '2'                 tri_up marker

    '3'                 tri_left marker

    '4'                 tri_right marker

    's'                 square marker

    'p'                 pentagon marker

    '*'                 star marker

    'h'                 hexagon1 marker

    'H'                 hexagon2 marker

    '+'                 plus marker

    'x'                 x marker

    'D'                 diamond marker

    'd'                 thin_diamond marker

    '|'                 vline marker

    '_'                 hline marker

    ================    ===============================

\end{lstlisting}

\subsection{Marker combinations}

\typ{In []: plot(x, y, 'ro')} \\

This plots figure with red colored filled circles.\\

Similarly other combination of colors and marker can be used.

\section{Lists}

Initializing

  \begin{lstlisting}

In []: mtlist = []      # Empty List

In []: lst = [ 1, 2, 3, 4, 5] 

  \end{lstlisting}

Slicing

\begin{lstlisting}

In []: lst[1:3]         # A slice.

Out[]: [2, 3]

In []: lst[1:-1]

Out[]: [2, 3, 4]

\end{lstlisting}

\subsection{Appending to lists}

\begin{lstlisting}

In []: a = [ 6, 7, 8, 9]

In []: b = lst + a

In []: b

Out[]: [1, 2, 3, 4, 5, 6, 7, 8, 9]

In []: lst.append(6)

In []: lst

Out[]: [ 1, 2, 3, 4, 5, 6]

\end{lstlisting}

\subsection{Iterating over a List}

\begin{lstlisting}

In []: for element in b:  # Iterating over the list, element-wise

 ....:     print element       # Print each element

 ....:

\end{lstlisting}

\section{Strings}

\subsection{Splitting Strings}

\begin{lstlisting}

In []: greet = ``hello world''

In []: print greet.split()

Out[]: ['hello', 'world']

In []: greet = ``hello, world''

In []: print greet.split(',')

Out[]: ['hello', ' world'] # Note the white space before 'world'

\end{lstlisting}

A string can be split based on the delimiter specified within quotes. A combination of more than one delimiter can also be used.\\

\typ{In []: greet.split(', ')}\\

\typ{Out[]: ['hello', 'world']}\\Note the white space is not there anymore.

\newpage

\section{Plotting from Files}

\subsection{Opening files}

\typ{In []: f = open('datafile.txt')}\\By default opens in read mode. \\If file does not exist then it throws an exception\\

\typ{In []: f = open('datafile.txt','r')}\\Specifying the read mode\\

\typ{In []: f = open('datafile.txt', 'w')}\\Opens the file in write mode. \\If the file already exists, then it deletes all the previous content and opens.

\subsection{Reading from files}

Just like lists files are iterable as well.

\begin{lstlisting}

  In []: for line in f:

    ...:     print line

    ...: 

    ...:

\end{lstlisting}

\subsection{Plotting}

\begin{lstlisting}

l = []

t = []

for line in open('pendulum.txt'):

    point = line.split()

    l.append(float(point[0]))

    t.append(float(point[1]))

tsq = []

for time in t:

    tsq.append(time*time)

plot(l, tsq, '.')

\end{lstlisting}

\end{document}