diff -r 88a01948450d -r d33698326409 plotting-data/script.rst --- a/plotting-data/script.rst Wed Nov 17 23:24:57 2010 +0530 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,218 +0,0 @@ -.. Objectives -.. ---------- - -.. By the end of this tutorial, you will be able to - -.. 1. Defining a list of numbers -.. 2. Squaring a list of numbers -.. 3. Plotting data points. -.. 4. Plotting errorbars. - - -.. Prerequisites -.. ------------- - -.. 1. getting started with plotting - - -.. Author : Amit - Internal Reviewer : Anoop Jacob Thomas - External Reviewer : - Checklist OK? : [2010-10-05] - -.. #[[Anoop: Add quickref]] -.. #[[Anoop: Slides are incomplete, add summary slide, thank you slide - etc.]] - -=============================== -Plotting Experimental Data -=============================== - -{{{ Show the slide containing title }}} - -Hello and welcome , this tutorial on Plotting Experimental data is -presented by the fossee team. - -{{{ Show the Outline Slide }}} - -.. #[[Anoop: outline slide is missing]] - -Here we will discuss plotting Experimental data. - -1. We will see how we can represent a sequence of numbers in Python. - -2. We will also become familiar with elementwise squaring of such a -sequence. - -3. How to plot data points using python. - -4. We will also see how we can use our graph to indicate Error. - -One needs to be familiar with the concepts of plotting -mathematical functions in Python. - -We will use data from a Simple Pendulum Experiment to illustrate. - -.. #[[Anoop: what do you mean by points here? if you mean the - points/numbered list in outline slide, then remove the usage point - from here.]] - -{{{ Simple Pendulum data Slide }}} - -.. #[[Anoop: slides are incomplete, work on slides and context - switches]] - - -As we know for a simple pendulum length,L is directly proportional to -the square of time,T. We shall be plotting L and T^2 values. - - -First we will have to initiate L and T values. We initiate them as sequence -of values. We define a sequence by comma seperated values inside two square brackets. -This is also called List.Lets create two sequences L and t. - -.. #[[Anoop: instead of saying "to tell ipython a sequence of values" - and make it complicated, we can tell, we define a sequence as]] - -.. #[[Anoop: sentence is incomplete, can be removed]] - -{{{ Show the initializing L&T slide }}} - -Type in ipython shell :: - - L = [0.1, 0.2, 0.3, 0.4, 0.5,0.6, 0.7, 0.8, 0.9] - - t= [0.69, 0.90, 1.19,1.30, 1.47, 1.58, 1.77, 1.83, 1.94] - - -To obtain the square of sequence t we will use the function square -with argument t.This is saved into the variable tsquare.:: - - tsquare=square(t) - tsqaure - array([ 0.4761, 0.81 , 1.4161, 1.69 , 2.1609, 2.4964, 3.1329, - 3.3489, 3.7636]) - -.. #[[Anoop: how do you get the array([ 0.4761 ....]) output?]] - - -Now to plot L vs T^2 we will simply type :: - - plot(L,tsquare,'.') - -.. #[[Anoop: be consistent with the spacing and all.]] - -'.' here represents to plot use small dots for the point. :: - - clf() - -You can also specify 'o' for big dots.:: - - plot(L,tsquare,'o') - - clf() - - -Following are exercises that you must do. - -%% %% Plot the given experimental data with large dots.The data is -on your screen. - -%% %% Plot the given experimental data with small dots. -The data is on your screen - - -Please, pause the video here. Do the exercises and then continue. - - - - - -.. #[[Anoop: Make sure code is correct, corrected plot(L,t,o) to - plot(L,t,'o')]] - - - -.. #[[Anoop: again slides are incomplete.]] - -For any experimental there is always an error in measurements due to -instrumental and human constaraints.Now we shall try and take into -account error into our plots . The Error values for L and T are on -your screen.We shall again intialize the sequence values in the same -manner as we did for L and t - -The error data we will use is on your screen. - -{{{ Show the Adding Error Slide }}} -.. #[[Anoop: give introduction to error and say what we are going to - do]] - -:: - - delta_L= [0.08,0.09,0.07,0.05,0.06,0.00,0.06,0.06,0.01] - delta_T= [0.04,0.08,0.03,0.05,0.03,0.03,0.04,0.07,0.08] - -Now to plot L vs T^2 with an error bar we use the function errorbar() - -The syntax of the command is as given on the screen. :: - - - errorbar(L,tsquare,xerr=delta_L, yerr=delta_T, fmt='b.') - -This gives a plot with error bar for x and y axis. The dots are of -blue color. The parameters xerr and yerr are error on x and y axis and -fmt is the format of the plot. - - -similarly we can draw the same error bar with big red dots just change -the parameters to fmt to 'ro'. :: - - clf() - errorbar(L,tsquare,xerr=delta_L, yerr=delta_T, fmt='ro') - - - -thats it. you can explore other options to errorbar using the documentation -of errorbar.:: - - errorbar? - -Following is an exercise that you must do. - -%% %% Plot the given experimental data with large green dots.Also include -the error in your plot. - -Please, pause the video here. Do the exercise and then continue. - - - - - - - -{{{ Show Summary Slide }}} - -In this tutorial we have learnt : - - - -1. How to declare a sequence of numbers. - -2. Plotting experimental data. - -#. The various options available for plotting dots instead of lines. - -#. Plotting experimental data such that we can also represent error. - - - - {{{ Show the "sponsored by FOSSEE" slide }}} - -.. #[[Anoop: again slides are incomplete]] - -This tutorial was created as a part of FOSSEE project. - -Hope you have enjoyed and found it useful. - -Thank You! -