syms x y z f g
x y z are symbolic
% x=(.051/4);
% y=(.01/2);
% z=(.005/4);
If those had the comment marks removed, the resulting x y z would be numeric and not integers
f(z,y,x) = cos(beta*z)*sin(mew*y)*cos(eta*x)*sin(eta*x);
When x, y, z are symbolic, that statement defines a symbolic function that relates symbolic names x, y, z to a formula.
When x, y, z are numeric, that statement calculates a specific numeric value on the right hand side, and tries to assign to to array f indexed at locations 0.00125, 0.005, 0.01275 . But those are not positive integers, so the indexing fails.
C_nmp_numerator = int(int(int(f,z,[0 (H/2)]),y,[0 W]),x,[0 (L/2)]);
If you had managed to fix the above f(z,y,x) definition so that f became a numeric scalar, then you would not be able to int() a numeric scalar.
