plotting and more about classes if we look at the codewe can deduce that this is plot showing the growth of an initial investment of $ , at an annually compounded interest rate of howeverthis cannot be easily inferred by looking only at the plot itself that' bad thing all plots should have informative titlesand all axes should be labeled if we add to the end of our the code the lines pylab title(' growthcompounded annually'pylab xlabel('years of compounding'pylab ylabel('value of principal ($)'we get the plot above and on the right for every plotted curvethere is an optional argument that is format string indicating the color and line type of the plot the letters and symbols of the format string are derived from those used in matlaband are composed of color indicator followed by line-style indicator the default format string is ' -'which produces solid blue line to plot the above with red circlesone would replace the call pylab plot(valuesby pylab plot(values'ro')which produces the plot on the right for complete list of color and line-style indicatorssee in order to keep the price downwe chose to publish this book in black and white that posed dilemmashould we discuss how to use color in plots or notwe concluded that color is too important to ignore if you want to see what the plots look like in colorrun the code