How to vectorize a for loop with array multiplication?

Please help on replacing:

for i=1:Nm

Sloctemp(i,:,:)=Sloctemp(i,:,:)*Sort(m,i);

end

Where Nm = 19 Sloctemp is a 30x6x6 matrix, Sort is a 524288x19 matrix m=1

Sort is populated with only 0 or ones, so I am just trying to multiply Sloctemp(1:19,:,:) by either 1 or 0.

I tried:

i=1:Nm;

Sloctemp(i,:,:)=Sort(m,i).*Sloctemp(i,:,:);

but get the "Array dimensions must match for binary array op." error.

This section of the code gets run tens of millions of times, so I am just trying to get the fastes solution.

Thank you!

Answer 1

[Jan]

Prefer to post the examples such, that they can be started by copy&paste.

Nm       = 19;
Sloctemp = rand(30, 6, 6);
Sort     = rand(524288, 19);
m        = 1;

Result = Sloctemp;
Result(1:19, :, :) = Sloctemp(1:19, :, :) .* Sort(m, 1:19).';

% Compare with original version:
for i = 1:Nm
    Sloctemp(i, :, :) = Sloctemp(i, :, :) * Sort(m, i);
end

max(abs(Result - Sloctemp), [], 'all')

[Erin Pratt]

Thank you Jan!