Python/C2/Usingtheplotcommandinteractively/English
From Script  SpokenTutorial
Visual Cue  Narration 

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containing title, name of the production team along with the logo of MHRD 
Hello Friends and welcome to the tutorial on creating simple plots using iPython. I hope you have IPython running on your computer. 
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Learning objective 
At the end of this tutorial, you will be able to,

ipython pylab  Lets start ipython. Open the terminal and type ipython pylab and hit enter. 
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Pylab is a python library which provides plotting functionality. It provides many other important mathematical and scientific functions. After running IPython pylab in the shell you will see some information about ipython and pylab followed by the In[1] prompt. But if you get an error like
`ERROR: matplotlib could NOT be imported! Starting normal IPython.` Then you will have to install the matplotlib and run this command again. 
Switch to terminal
linspace? 
Now type 'linspace' followed by a '?' mark in your ipython shell 
linspace(1,100,100)  as the documentation says, it returns num evenly spaced samples, calculated over the interval start and stop. To illustrate this, lets try to generate 100 points. Type linspace(1,100,100) and hit enter. As you can see a sequence of numbers from 1 to 100 appears. 
linspace(0,1,200)  Now lets try to generate 200 points between 0 and 1,we do that by typing linspace(0,1,200). 
p = linspace(pi,pi,100)  Here,0 is the start , 1 the stop and 200 the number 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. Here 'pi' is a constant defined by pylab. Save this to the variable,say p. 
len(p)  If we now type len(p)``we will get the no. of points. ``len function gives the no of elements of a sequence. 
plot(p,cos(p))  Let's try and plot a cosine curve between pi and pi. For this we use the plot command. Here cos(p) gets the cosine value at every point corresponding to point p. 
cosine=cos(p)
plot(p,cosine) 
We can save cos(p) to variable cosine and then plot it using the plot function. 
clf()  Now to clear the plot ,we use the clf() function 
plot(p,sin(p))  This is done because if we wish to make another plot, it will overlap the previous plot. As we do not wish to clutter the area with overlaid plots , we just clear it with clf(). Now lets try a sine plot. 
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'Plot UI' 
We can study the plot better on the plot window by using the various options available on it. Let us have a look at these options. 
Move the mouse along the plot  As we can observe, moving the mouse pointer along the plot gives us the location of each point on the plot 
Save the plot as sin_curve in pdf format  To the bottom left of the window,there are a few buttons. The right most among them is for saving the file. Just click on it and type the file name. We will save the plot by the name sin_curve in pdf format. As you can see we can specify the format of file from the dropdown. Formats like png ,eps ,pdf, ps are available. 
Point the mouse on the slider button  Left to the save button is the slider button by which we can specify the margins. 
Show how to zoom. Press zoom button and specify region to zoom  Left to this is the zoom button by which we can zoom into the plot. Just specify the region to zoom into. 
Press Move button and move the axes.  The button to the left of it can be used to move the axes of the plot. 
Press Back and Forward Button  The next two buttons with 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 the back and forward button in a browser. 
Press home button  The last one is 'home' referring to the initial plot. 
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Assignment 1 
Pause the video here, try out the following exercise and resume the video.
Plot (sin(x)*sin(x))/x.

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Summary Slide 
This brings us to the end of this tutorial.In this tutorial,we have learnt to,

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Self assessment questions slide 
Here are some self assessment questions for you to solve

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Solution of self assessment questions slide 
And the answers,

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Acknowledgment slide 
Hope you have enjoyed and found it useful. Thank you! 