optimization - High time complexity reduction of the matlab code -


i trying run piece of code in matlab has high complexity despite matlab slow loops. please me optimize code below.

for k=1:th     i=1:d-1         j=i+1:d             if(dist(j,k)>dist(i,k))                 t=classp1(k,i);                 classp1(k,i)=classp1(k,j);                 classp1(k,j)=t;             end         end     end end

where

size(classp1)=20x4276

size(dist)=4276x20

thank lot in advance

rinadi

you might able remove outer loop on k (untested since don't have data, might need tweaking):

for = 1:d-1     j = i+1:d         iswap = find(dist(j, 1:th) > dist(i, 1:th));         classp1(iswap, [i, j]) = classp1(iswap, [j, i])     end end

i not sure if saves lot in readability or in speed.

but goal? seems doing sorting matrix classp1 based on matrix dist (but not exactly). maybe there better solution using [~, idx] = sort(dist) , classp1(??, idx) = whatever.


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