Greg Reeves

I took out the for loops and just used array algebra to do essentially the same thing. Improved speed ~10 fold. I didn't bother checking whether edge behavior is the same. My edge behavior is similar to the default behavior in Matlab's builtin smooth function.

%Initial error statements and definitions
if nargin<2, error('Not enough input arguments!'), end

N(1) = Nr;
if nargin<3
    N(2) = N(1);
else
    N(2) = Nc;
end

if length(N(1))~=1, error('Nr must be a scalar!'), end
if length(N(2))~=1, error('Nc must be a scalar!'), end

[row,col] = size(matrixIn);
eL = spdiags(ones(row,2*N(1)+1),(-N(1):N(1)),row,row);
eL = eL./(repmat(sum(eL,1),row,1));
eR = spdiags(ones(col,2*N(2)+1),(-N(2):N(2)),col,col);
eR = eR./(repmat(sum(eR,2),1,col));

matrixOut = eL*matrixIn*eR;

Thanks.

I experienced vertical and horizontal jumps when using the smooth2 procedure and spent quite a while tracking down something better when I stumbled across the list of work the smooth2 had inspired (yours being one of them). smooth2a completely resolved the issue. I thank you for this!