The plotdensity or densityplot command draws the graph of a function of two variables in the plane where the values of z are represented by the rainbow colors.
Instead of xstep and ystep, you could use the option nstep=n to specify the number of points used to graph.
A rectangle representing the scale of colors will be displayed below the graph.
plotdensity(x^2-y^2,[x=-2..2,y=-2..2],xstep=0.1,ystep=0.1) |