using-plot-interactively/script.rst
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    19    External Reviewer   :
    19    External Reviewer   :
    20    Checklist OK?       : <put date stamp here, if OK> [2010-10-05]
    20    Checklist OK?       : <put date stamp here, if OK> [2010-10-05]
    21 
    21 
    22 Script
    22 Script
    23 -------
    23 -------
    24 
    24 {{{ Show the Title Slide }}} 
    25 
    25 
    26 Hello and welcome to the tutorial on creating simple plots using
    26 Hello and welcome to the tutorial on creating simple plots using
    27 Python.This tutorial is presented by the Fossee group.  
    27 Python.This tutorial is presented by the Fossee group.  
    28 {{{ Show the Title Slide }}} 
       
    29 
    28 
    30 I hope you have IPython running on your computer.
    29 I hope you have IPython running on your computer.
    31 
    30 
    32 In this tutorial we will look at plot command and also how to study
    31 In this tutorial we will look at plot command and also how to study
    33 the plot using the UI.
    32 the plot using the UI.
    50 
    49 
    51 
    50 
    52 {{{ Slide with Error written on it }}}
    51 {{{ Slide with Error written on it }}}
    53 
    52 
    54 
    53 
    55 
       
    56 
       
    57 Then you have to install matplotlib and run this command again.
    54 Then you have to install matplotlib and run this command again.
    58 
    55 
    59 Now type in your ipython shell ::
    56 Now type in your ipython shell ::
    60 
    57 
    61              In[]: linpace?
    58              linpace?
    62 
    59 
    63 
    60 
    64 
    61 
    65 as the documentation says, it returns `num` evenly spaced samples,
    62 as the documentation says, it returns `num` evenly spaced samples,
    66 calculated over the interval start and stop.  To illustrate this, lets
    63 calculated over the interval start and stop.  To illustrate this, lets
    67 do it form 1 to 100 and try 100 points.  ::
    64 do it form 1 to 100 and try 100 points.  ::
    68 
    65 
    69            In[]: linspace(1,100,100)
    66             linspace(1,100,100)
    70 
    67 
    71 As you can see a sequence of numbers from 1 to 100 appears.
    68 As you can see a sequence of numbers from 1 to 100 appears.
    72 
    69 
    73 Now lets try 200 points between 0 and 1 you do this by typing ::
    70 Now lets try 200 points between 0 and 1 you do this by typing ::
    74 
    71 
    75 
    72 
    76             In[]: linspace(0,1,200)
    73              linspace(0,1,200)
    77 
    74 
    78 0 for start , 1 for stop and 200 for no of points.  In linspace 
    75 0 for start , 1 for stop and 200 for no of points.  In linspace 
    79 the start and stop points can be integers, decimals , or
    76 the start and stop points can be integers, decimals , or
    80 constants. Let's try and get 100 points between -pi to pi. Type ::
    77 constants. Let's try and get 100 points between -pi to pi. Type ::
    81            
    78            
    82             In[]: p = linspace(-pi,pi,100)
    79              p = linspace(-pi,pi,100)
    83 
    80 
    84 
    81 
    85 'pi' here is constant defined by pylab. Save this to the variable, p
    82 'pi' here is constant defined by pylab. Save this to the variable, p
    86 .
    83 .
    87 
    84 
    88 If you now ::
    85 If you now ::
    89      
    86      
    90 	   In[]: len(p)
    87 	    len(p)
    91 
    88 
    92 You will get the no. of points. len function gives the no of elements
    89 You will get the no. of points. len function gives the no of elements
    93 of a sequence.
    90 of a sequence.
    94 
    91 
    95 
    92 
    96 Let's try and plot a cosine curve between -pi and pi using these
    93 Let's try and plot a cosine curve between -pi and pi using these
    97 points.  Simply type :: 
    94 points.  Simply type::
    98 
    95 
    99 
    96 	 plot(p,cos(points)) 
   100        	  In[]: plot(p,cos(points))
    97 
   101 
    98 
   102 Here cos(points) gets the cosine value at every corresponding point to
    99 Here cos(points) gets the cosine value at every corresponding point to
   103 p.
   100 p.
   104 
   101 
   105 
   102 
   106 We can also save cos(points) to variable cosine and plot it using
   103 We can also save cos(points) to variable cosine and plot it using
   107 plot.::
   104 plot.::
   108 
   105 
   109            In[]: cosine=cos(points) 
   106           cosine=cos(points) 
   110 
   107 
   111 	   In[]: plot(p,cosine)
   108 	  plot(p,cosine)
   112 
   109 
   113  
   110  
   114 
   111 
   115 Now do ::
   112 Now do ::
   116        	 
   113        	 
   117 	   In[]: clf()
   114 	  clf()
   118 
   115 
   119 this will clear the plot.
   116 this will clear the plot.
   120 
   117 
   121 This is done because any other plot we try to make shall come on the
   118 This is done because any other plot we try to make shall come on the
   122 same drawing area. As we do not wish to clutter the area with
   119 same drawing area. As we do not wish to clutter the area with
   123 overlaid plots , we just clear it with clf().  Now lets try a sine
   120 overlaid plots , we just clear it with clf().  Now lets try a sine
   124 plot. ::
   121 plot. ::
   125 
   122 
   126 
   123 
   127     	 In []: plot(p,sin(p))
   124     	  plot(p,sin(p))
   128 
   125 
   129 
   126 
   130 
   127 
   131  
   128  
   132 The Window on which the plot appears can be used to study it better.
   129 The Window on which the plot appears can be used to study it better.
   142 Just click on it specifying the name of the file.  We will save the plot 
   139 Just click on it specifying the name of the file.  We will save the plot 
   143 by the name sin_curve in pdf format.
   140 by the name sin_curve in pdf format.
   144 
   141 
   145 
   142 
   146 
   143 
   147 {{{ Action corelating with the words }}}
   144 {{{ Show how to save the file  }}}
   148 
   145 
   149 As you can see I can specify format of file from the dropdown.
   146 As you can see I can specify format of file from the dropdown.
   150 
   147 
   151 Formats like png ,eps ,pdf, ps are available.  
   148 Formats like png ,eps ,pdf, ps are available.
   152 
   149 
   153 Left to the save button is the slider button to specify the margins.  
   150 Left to the save button is the slider button to specify the margins.
   154 
   151 
   155 {{{ Action corelating with the words  }}}
   152 {{{ Show how to zoom. Press zoom button and specify region to zoom }}}
   156 
   153 
   157 Left to this is zoom button to zoom into the plot. Just specify the 
   154 Left to this is zoom button to zoom into the plot. Just specify the 
   158 region to zoom into.  
   155 region to zoom into.  
       
   156 
       
   157 {{{ Press Move button and move the axes. }}}
       
   158 
   159 The button left to it can be used to move the axes of the plot.  
   159 The button left to it can be used to move the axes of the plot.  
   160 
   160 
   161 {{{ Action corelating with the words }}}
   161 {{{ Press Back and Forward Button }}}
   162  
   162  
   163 The next two buttons with a left and right arrow icons change the state of the 
   163 The next two buttons with a left and right arrow icons change the state of the 
   164 plot and take it to the previous state it was in. It more or less acts like a
   164 plot and take it to the previous state it was in. It more or less acts like a
   165 back and forward button in the browser.  
   165 back and forward button in the browser.  
   166 
   166 
   167 {{{ Action corelating with the words }}}
   167 {{{ Press home button }}}
   168 
   168 
   169 The last one is 'home' referring to the initial plot.
   169 The last one is 'home' referring to the initial plot.
   170 
   170 
   171 {{{ Action corelating with the words}}}
   171 
       
   172 
       
   173 
       
   174 Following is an  exercise that you must do. 
       
   175 
       
   176 %% %% Plot (sin(x)*sin(x))/x .
       
   177       1. Save the plot by the sinsquarebyx.pdf in pdf format.
       
   178       2. Zoom and find the maxima.
       
   179 
       
   180       3. Bring it back to initial position.
       
   181 
       
   182 
       
   183 Please, pause the video here. Do the exercise and then continue. 
       
   184 
       
   185 
       
   186 
       
   187 
       
   188 
       
   189 
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   190 
   173 
   191 
   174 
   192 
   175 {{{ Summary Slide }}}
   193 {{{ Summary Slide }}}
   176 
   194 
   177 
       
   178 In this tutorial we have looked at 
   195 In this tutorial we have looked at 
   179 
   196 
   180 1. Starting Ipython with pylab 
   197 1. Starting Ipython with pylab 
   181 
   198 
   182 2. Using linspace function to create `num` equaly spaced points in a region.
   199 2. Using linspace function to create `num` equaly spaced points in a region.
   188 4. Clearing drawing area using clf 
   205 4. Clearing drawing area using clf 
   189  
   206  
   190 5. Using the UI of plot for studying it better . Using functionalities like save , zoom and moving the plots on x and y axis 
   207 5. Using the UI of plot for studying it better . Using functionalities like save , zoom and moving the plots on x and y axis 
   191 
   208 
   192 
   209 
   193  
   210  {{{ Show the "sponsored by FOSSEE" slide }}}
   194 
       
   195 
       
   196 {{{ Show the "sponsored by FOSSEE" slide }}}
       
   197 
   211 
   198  
   212  
   199 
   213 
   200 This tutorial was created as a part of FOSSEE project, NME ICT, MHRD India
   214 This tutorial was created as a part of FOSSEE project, NME ICT, MHRD India
   201 
   215