HELP copy matrix and inserting in another matrix

Hello guys, i have a matrix

U=(416,411)

and i need to make a matrix

W=zeros(416+2,411+2)

and then i need to copy the matrix U inside the matrix W, so the borders of this new matrix become full of zeros, or in anothers words matrix U surrended by zeros.

For example:

[0 0 0 0 ...
 0 1 1 0 ...
 0 0 0 0]
´
thanks in advance

Answer 1

[dpb]

W(2:end-1,2:end-1)=U;

using the fact size(W you already created is size(U)+2 and you wanted it centered. If it weren't centered, then the generic expression is written based on the size of U instead of W...

r1=2; c1=2  % row column starting points in target
[nr,nc]=size(U);  
r2=r1+nr-1: c2=c1+nc-1; % end positions in W
W(r1:r2,c1:c2)=U;

The rule is the size() of the LHS addressing expression has to match that of the RHS.

[Jah-lahfui]

yeah thanks a lot! You just made me felt dumb ehehe thanks!

Answer 2

[Azzi Abdelmalek]

[n,m]=size(U)
W(1:n,1:m)=U

[dpb]

Just as a minor correction, the above places it in upper RH corner, Azzi...need correction for the offset to get it at the desired starting location.