Is it possible to make combvec function faster

Hi All, After running my code with matlab profiler I see that combvec function is taking the most time. Is it possible to use any other function which is faster than combvec or is there are any other functions which is more useful parallel processing?

thanks in advance

[Jan]

Please post the relevant part of the code and which inputs you use. It matters if you call combvec millions of times for small inputs or once for a huge input, of if you operator on many small vectors or a few big matrices.

[Stephen23]

Raihan Ul Islam's "Answer" moved here and formatted correctly:

Here transformedRefVal size can be 310*5*5 and attrWeight size can be 5

for i=1:size(transformedRefVal,3)
    transformedRefVal(:,:,i)=power(transformedRefVal(:,:,i),attrWeight(i));
    if i==1
        xb3=combvec(transformedRefVal(:,:,i));
    else
        xb3=combvec(xb3,transformedRefVal(:,:,i));
    end
end

Answer 1

[Jan]

You can inline the code of combvec:

X = rand(310, 5, 5);
Y = rand(1, 5);

sX = size(X, 2);
for i = 1:size(X, 3)
   X(:,:,i) = power(X(:,:,i), Y(i));
   if i == 1
     xb3 = X(:,:,i);  % combvec(X) is the same as X
   else
     s1  = size(xb3, 2);
     xb3 = [repmat(xb3, 1, sX); repelem(X(:,:,i), 1, s1)];
   end
end

This take 3.8 seconds on my R2016b, instead of 4.8 seconds of the original version.

[Raihan Ul Islam]

Thanks for the solution.