How can I pass 2-D meshgridded var into a 3-D matrix?

I need to pass X and Y which are 2-D meshgridded matrices into c the 3-D matrix. where k is a constant and zv is a vector.

Here is my try:

for i = 1:M
    c(:,:,i)=exp(1j*k/(2*zv(i))*(X2.^2+Y2.^2));
end

Thanks.

[Stephen23]

@Ezz El-din Abdullah: What is your question?

[Ezz El-din Abdullah]

As shown from the title.

I would like to see what edits should I make on my provided code to get the problem solved because it produces this error:

Subscripted assignment dimension mismatch.

[Steven Lord]

Show us the sizes of all of X2, Y2, c, and zv as well as the value of M as they are immediately before you enter the loop.

[Ezz El-din Abdullah]

M is 250

X2 is 250x250

Y2 is 250x250

c is not defined before the loop but I want it to be 3D matrix (250x250x250)

Answer 1

[Guillaume]

Step 1: permute your vector so that it is along the 3rd dimension:

zv = permute(zv, [3 2 1]);  %if zv is a column vector (M x 1)
%or
zv = permute(zv, [1 3 2]);  %if zv is a row vector (1 x M)

Step 2: No need for loop, use memberwise operation + implicit expansion (if on R2016b or later):

c = exp(1j*k./(2*zv)) .* (X2.^2 + Y2.^2));

If on version < R2016b:

c = bsxfun(@times, exp(1j*k./(2*zv)), (X2.^2 + Y2.^2));

[Ezz El-din Abdullah]

Thank you, but this will produce another error for the 2-D matrices X and Y:

Error using  .* 
Matrix dimensions must agree.

[Guillaume]

What is

size(zv)  %after the permute
size(X2)
size(Y2)

and which version of matlab?

[Ezz El-din Abdullah]

zv is 1x250 while after the permute it is 1x1x250 where M = 250

X2 is 250x250

Y2 is 250x250

I'm using R2016a

[Ezz El-din Abdullah]

I'm using R2016a

[Guillaume]

As I wrote,

If on version < R2016b:

c = bsxfun(@times, exp(1j*k./(2*zv)), (X2.^2 + Y2.^2)); %after the permute

[Ezz El-din Abdullah]

Thank you very much.