zmf compute the z-shaped member function of x
with parameters [a,b,c,d].
Examples
x=linspace(0,1,100)';y1=pimf(x,[0.10.40.91.0]);y2=pimf(x,[0.30.60.70.8]);y3=pimf(x,[0.40.70.60.8]);scf();clf();plot2d(x,[y1y2y3],leg="y1@y2@y3");xtitle("Pi-Shaped Member Function Example","x","mu(x)");