* Script

Lets start ipython. Open up your terminal and type the following. 

$ ipython -pylab

This will give us a prompt where we can get started. 

In []: x = linspace(0, 2*pi, 100)

We have passed three arguments to linspace function - the first point, the last point and the total number of points. 

lets see what is x

In []: x

 x is a sequence of 100 points starting from 0 to 2*pi. 

In []: len(x)

 Shows the length of x to be 100 points. 

To obtain the plot we say, 

In []: plot(x, sin(x))

It gives a plot of x vs y, where y is sin values of x, with the default color and line properties. 

Both 'pi' and 'sin' come from 'pylab'. 

Now that we have a basic plot, we can label and title the plot. 

In []: xlabel('x') adds a label to the x-axis. Note that 'x' is enclosed in quotes. 

In []: ylabel('sin(x)') adds a label to the y-axis. 

In []: title('Sinusoid') adds a title to the plot. 

Now we add a legend to the plot. 

In []: legend(['sin(x)'])

We can specify the location of the legend, by passing an additional argument to the function. 

In []: legend(['sin(2y)'], loc = 'center')

other positions which can be tried are 

'best' 

'right'

We now annotate, i.e add a comment at, the point with maximum sin value. 

In []: annotate('local max', xy=(1.5, 1))

The first argument is the comment and second one is the position for it. 

Now, we save the plot 

In []: savefig('sin.png') saves the figure as sin.png in current directory. 

?#other supported formats are: eps, emf, ps, pdf, ps, raw, rgba, svg

and finally to close the plot

In []: close()

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