Initial Commit of simple plotting and plot user interface
authoramit
Thu, 16 Sep 2010 19:31:15 +0530
changeset 147 fe7aad827c9c
parent 146 b92b4e7ecd7b
child 148 60a4616dbf55
Initial Commit of simple plotting and plot user interface
plotui.rst
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/plotui.rst	Thu Sep 16 19:31:15 2010 +0530
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+Hello and welcome to the tutorial on creating simple plots using
+Python.This tutorial is presented by the Fossee group.  
+{{{ Show the Title Slide }}} 
+
+I hope you have IPython running on your computer.
+
+In this tutorial we will look at plot command and also how to study
+the plot using the UI.
+
+{{{ Show Outline Slide }}}
+
+Lets start ipython on your shell, type :: 
+
+      $ipython -pylab
+
+
+Pylab is a python library which provides plotting functionality.It
+also provides many other important mathematical and scientific
+functions. After running IPython -pylab in your shell if at the top of
+the result of this command, you see something like ::
+ 
+
+   `ERROR: matplotlib could NOT be imported!  Starting normal
+      IPython.`
+
+
+{{{ Slide with Error written on it }}}
+
+Then you have to install matplotlib and run this command again.
+
+Now type in your ipython shell ::
+
+             In[]: linpace?
+
+
+
+as the documentation says, it returns `num` evenly spaced samples,
+calculated over the interval start and stop.  To illustrate this, lets
+do it form 1 to 100 and try 100 points.  ::
+
+           In[]: linspace(1,100,100)
+
+As you can see a sequence of numbers from 1 to 100 appears.
+
+Now lets try 200 points between 0 and 1 you do this by typing ::
+
+
+            In[]: linspace(0,1,200)
+
+0 for start , 1 for stop and 200 for no of points.  In linspace 
+the start and stop points can be integers, decimals , or
+constants. Let's try and get 100 points between -pi to pi. Type ::
+           
+            In[]: p = linspace(-pi,pi,100)
+
+
+'pi' here is constant defined by pylab. Save this to the variable, p
+.
+
+If you now ::
+     
+	   In[]: len(p)
+
+You will get the no. of points. len function gives the no of elements
+of a sequence.
+
+
+Let's try and plot a cosine curve between -pi and pi using these
+points.  Simply type :: 
+
+
+       	  In[]: plot(p,cos(points))
+
+Here cos(points) gets the cosine value at every corresponding point to
+p.
+
+
+We can also save cos(points) to variable cosine and plot it using
+plot.::
+
+           In[]: cosine=cos(points) 
+
+	   In[]: plot(p,cosine)
+
+ 
+
+Now do ::
+       	 
+	   In[]: clf()
+
+this will clear the plot.
+
+This is done because any other plot we try to make shall come on the
+same drawing area. As we do not wish to clutter the area with
+overlaid plots , we just clear it with clf().  Now lets try a sine
+plot. ::
+
+
+    	 In []: plot(p,sin(p))
+
+
+
+ 
+The Window on which the plot appears can be used to study it better.
+
+First of all moving the mouse around gives us the point where mouse
+points at.  
+
+Also we have some buttons the right most among them is
+for saving the file. 
+
+Just click on it specifying the name of the file.  We will save the plot 
+by the name sin_curve in pdf format.
+
+{{{ Action corelating with the words }}}
+
+As you can see I can specify format of file.  
+Left to the save button is the slider button to specify the margins.  
+
+{{{ Action corelating with the words  }}}
+
+Left to this is zoom button to zoom into the plot. Just specify the 
+region to zoom into.  
+The button left to it can be used to move the axes of the plot.  
+
+{{{ Action corelating with the words }}}
+ 
+The next two buttons with a left and right arrow icons change the state of the 
+plot and take it to the previous state it was in. It more or less acts like a
+back and forward button in the browser.  
+
+{{{ Action corelating with the words }}}
+
+The last one is 'home' referring to the initial plot.
+
+{{{ Action corelating with the words}}}
+
+
+
+{{{ Summary Slide }}}
+
+
+In this tutorial we have looked at 
+
+1. Starting Ipython with pylab 
+
+2. Using linspace function to create `num` equaly spaced points in a region.
+
+3. Finding length of sequnces using  len.
+ 
+4. Plotting mathematical functions using plot.
+
+4. Clearing drawing area using clf 
+ 
+5. Using the UI of plot for studying it better . Using functionalities like save , zoom , moving the plots on x and y axis 
+
+etc ..
+ 
+
+
+{{{ Show the "sponsored by FOSSEE" slide }}}
+
+ 
+
+This tutorial was created as a part of FOSSEE project, NME ICT, MHRD India
+
+ 
+
+ Hope you have enjoyed and found it useful.
+
+ Thankyou
+
+ 
+
+Author              : Amit Sethi
+Internal Reviewer   :
+Internal Reviewer 2 :