Speedup/Refaktoring loop?

[Andreas Romeyke]

Hi,

There are any tricks to speedup the following piece of code?

    for i=1:n
        a=transpose(U) * X;
        tmpU = transpose(U)*U;
        for j=1:columns
            b=tmpU*V;
            V(i,j)=V(i,j)* a(i,j)/b(i,j);
        end
    end

U and V are rectangular matrices, X is a squared matrix.

The variant to replace line "V(i,j)=V(i,j)* a(i,j)/b(i,j);" with

"V = V .* a ./ b" is much slower.

I used Octave 2.9.9 to time the code.

Any hints?

Bye Andreas



-- 
Software Developer / Dipl. Inform. (FH)
Max Planck Institute for Human Cognitive and Brain Sciences
Department of Psychology
Stephanstr. 1a, 04103 Leipzig, Germany

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