How can I change the limits of axis in 3d plot

I wrote this code but I couldn't change the axis limits, do you know what is the problem?

w3=20:100;
t=0:0.01:5;
w=107.36; d=150; x=410;
[a,b]=meshgrid(w3,t);
z=abs((4.22E-3)*(a.^2)./((w.^2)-(a.^2))).*sin((pi*d)/820).*sin((pi*x)/820).*sin(a.*b);
figure
sa=surf(a,b,z, 'EdgeColor','none')
aH = ancestor(sa,'axes')
set(aH,'yLim',[20 100])

Answer 1

[Walter Roberson]

Setting the limit is working. However, your b values are only in the range 0 to 5, and you are setting the limit to be 20 to 100, and there is no data to show for that range of values. 20 to 100 is what you would want for your a values, not for your b values.