diff -r 88a01948450d -r d33698326409 using-plot-interactively/script.rst --- a/using-plot-interactively/script.rst Wed Nov 17 23:24:57 2010 +0530 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,226 +0,0 @@ -.. Objectives -.. ---------- - -.. By the end of this tutorial you will -- - -.. 1. Create simple plots of mathematical functions -.. #. Use the Figure window to study plots better - - - -.. Prerequisites -.. ------------- - -.. Installation of required tools -.. Ipython - -.. Author : Amit Sethi - Internal Reviewer : - External Reviewer : - Checklist OK? : [2010-10-05] - -Script -------- -{{{ Show the Title Slide }}} - -Hello and welcome to the tutorial on creating simple plots using -Python.This tutorial is presented by the Fossee group. - -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 :: - - 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. :: - - 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 :: - - - 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 :: - - p = linspace(-pi,pi,100) - - -'pi' here is constant defined by pylab. Save this to the variable, p -. - -If you now :: - - 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:: - - 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.:: - - cosine=cos(points) - - plot(p,cosine) - - - -Now do :: - - 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. :: - - - plot(p,sin(p)) - - - - -The Window on which the plot appears can be used to study it better. - -{{{ Show the slide with all the buttons on it }}} - -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. - - - -{{{ Show how to save the file }}} - -As you can see I can specify format of file from the dropdown. - -Formats like png ,eps ,pdf, ps are available. - -Left to the save button is the slider button to specify the margins. - -{{{ Show how to zoom. Press zoom button and specify region to zoom }}} - -Left to this is zoom button to zoom into the plot. Just specify the -region to zoom into. - -{{{ Press Move button and move the axes. }}} - -The button left to it can be used to move the axes of the plot. - -{{{ Press Back and Forward Button }}} - -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. - -{{{ Press home button }}} - -The last one is 'home' referring to the initial plot. - - - - -Following is an exercise that you must do. - -%% %% Plot (sin(x)*sin(x))/x . - 1. Save the plot by the sinsquarebyx.pdf in pdf format. - 2. Zoom and find the maxima. - - 3. Bring it back to initial position. - - -Please, pause the video here. Do the exercise and then continue. - - - - - - - - - -{{{ 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 and moving the plots on x and y axis - - - {{{ 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 :