often text is the best way to communicate informationbut sometimes there is lot of truth to the chinese proverb(" picture' meaning can express ten thousand words"yet most programs rely on textual output to communicate with their users whybecause in many programming languages presenting visual data is too hard fortunatelyit is simple to do in python plotting using pylab pylab is python standard library module that provides many of the facilities of matlab" high-level technical computing language and interactive environment for algorithm developmentdata visualizationdata analysisand numeric computation " later in the bookwe will look at some of the more advanced features of pylabbut in this we focus on some of its facilities for plotting data complete user' guide for pylab is at the web site matplotlib sourceforge net/users/index html there are also number of web sites that provide excellent tutorials we will not try to provide user' guide or complete tutorial here insteadin this we will merely provide few example plots and explain the code that generated them other examples appear in later let' start with simple example that uses pylab plot to produce two plots executing import pylab pylab figure( #create figure pylab plot([ , , , ][ , , , ]#draw on figure pylab show(#show figure on screen will cause window to appear on your computer monitor its exact appearance may depend on the operating system on your machinebut it will look similar to the following