\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 from Data files}

\begin{verbatim}

l = [] #Empty List

t = []

for line in open('pendulum.txt'): # Opening & Reading files

    points = line.split() # Splitting a string

    l.append(float(points[0])) # Appending to a list

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

tsq = []

for time in t:  #Iterating through lists

    tsq.append(t*t)

plot(l, tsq, '.') # Plotting points

\end{verbatim}

\section{Plotting Points with Lists}

\begin{lstlisting}

In [1]: x = [0, 1, 2, 3]

In [2]: y = [7, 11, 15, 19]

In [3]: plot(x, y)

In [4]: clf()

In [5]: plot(x, y, 'o')  # Plotting Circles

#Dots - '.', #Dashed lines - '--' #Lines - '-'

\end{lstlisting}

\section{Lists}

Initializing

  \begin{lstlisting}

In [10]: mtlist = []      # Empty List

In [11]: lst = [ 1, 2, 3, 4, 5] 

  \end{lstlisting}

Slicing

\begin{lstlisting}

In [12]: lst[1:3]         # A slice.

Out[12]: [2, 3]

In [13]: lst[1:-1]

Out[13]: [2, 3, 4]

\end{lstlisting}

Appending to lists

\begin{lstlisting}

In [14]: a = [ 6, 7, 8, 9]

In [15]: b = lst + a

In [16]: b

Out[16]: [1, 2, 3, 4, 5, 6, 7, 8, 9]

In [17]: lst.append(6)

In [18]: lst

Out[18]: [ 1, 2, 3, 4, 5, 6]

\end{lstlisting}

Iterating over a List

\begin{lstlisting}

In [19]: for each in b:  # Iterating over the list, element-wise

 ....:     print b       # Print each element

 ....:

\end{lstlisting}

Splitting Strings

\begin{lstlisting}

In [20]: line = '1.2000e-01 7.4252e-01'

In [21]: point = line.split()    # Splits the string at the space

Out[21]: ['1.2000e-01', '7.4252e-01']

\end{lstlisting}

Plotting from Files

\begin{lstlisting}

In [22]: L = []

In [23]: T = []

#Open a file & operate on each line

In [24]: for line in open('pendulum.txt'):  

  ....     point = line.split()

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

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

In [25]: TSq = []

In [26]: for t in T:

 ....:     TSq.append(t*t)

 ....:     

 ....:     

In [27]: plot(L, TSq, '.')

\end{lstlisting}

\end{document}