Z is not matrix for surf(X,Y,Z)

I am trying to plot surf(X,Y,Z) but my Z is not a matrix.

TH = [0:0.05*pi:2*pi ];
R = [0:0.5:20];
[X,Y] =pol2cart(TH,R);
[X,Y] = meshgrid(X,Y)
Z = (abs((sqrt(2)/(81*sqrt(pi))).*(6.*R-R.^2).*exp(-R./3).*cos(TH))).^2

Im hoping someone can look over my code and help me out. Thanks

Answer 1

[KSSV]

TH = [0:0.05*pi:2*pi ]; 
R = [0:0.5:20]; 
[X,Y] =pol2cart(TH,R); 
[X,Y] = meshgrid(X,Y) ;
[R,TH] = meshgrid(R,TH) ;
Z = (abs((sqrt(2)/(81*sqrt(pi))).*(6.*R-R.^2).*exp(-R./3).*cos(TH))).^2 ;
figure
surf(R,TH,Z)
figure
surf(X,Y,Z)

[darlene yen]

thanks

[darlene yen]

 for some reason, the code doesn't run out to be desired answer. the dimensions are all correct but not the value. 

 for original function is

Answer 2

[Prachi Sikaria]

what is the relation of z in surf(x y z)