MATLAB For Dummies

Appendix B

MATLAB’s Plotting Routines

This appendix lists the plotting routines in MATLAB with a brief description and example. To save space, some entries show a single encompassing example for multiple commands. An example may also use an ellipsis (...) to show the continuation of a pattern. To assist you, we have included several functions to generate test matrices, for example, rand(), magic(), peaks(), cylinder(), ellipsoid(), and sphere().

Table B-1 Basic Plotting Routines

Routine	Description	Example
ezplot	Plots the expression enclosed in quotes	ezplot('exp(-0.4*x)*sin(x)')
fplot	Same as ezplot, but requires limits	fplot('exp(-0.4*x)*sin(x)',[0,2*pi,-0.3,0.6])
plot	Plots data passed in by vectors	x=[0:2*pi/100:2*pi]; y=exp(-0.4*x).*sin(x); plot(x,y); figure(2) comet(x,y); figure(3) ribbon(x,y);figure(4) y2=100*exp(-0.4*x).*cos(x); plotyy(x,y,x,y2)
comet	Just like plot, but comet animates the trajectory. It helps to have a larger vector to slow down the comet trace a tad
ribbon	Like plot, but it displays the data as 3D ribbons
plotyy	Plots data where y values may differ greatly — it makes two y-axes
loglog	Plots data on a log scale on both x- and y-axes — y proportional to a power of x is straight on this plot	x=[0:2*pi/100:2*pi]; y=10*x.^pi; loglog(x,y)
semilogx	X-axis data is on a log scale and the y-axis is on a linear scale — y linearly related to log(x) is straight on this plot	x=[0:2*pi/100:2*pi]; y=10*log(x)+pi; ...