data assingment issue in parfor loop

Hi:

I tried to assign matrix to pre-allocated variable "A" in "parfor" loop but failed, error message says: "Error: Unable to classify the variable 'A' in the body of the parfor-loop. For more information, see Parallel for Loops in MATLAB, "Solve Variable Classification Issues in parfor-Loops"

the technical issue I'm facing is that, the "numberIdx" is a variable that needs to be determined inside the for-loop, i.e. it is not a fixed value.

is there any way to improve my script?

Thanks!

A=ones(10,10);
parfor idx=1:1:10
    numberIdx=2:2:8;
    A(idx,numberIdx)=0;
end

Answer 1

[Walter Roberson]

A=ones(10,10);
parfor idx=1:1:10
  Arow = A(idx, :) ;
  numberIdx=2:2:8;
  Arow(numberIdx)=0;
  A(idx, :) = Arow;
end

Yes, you copy some existing elements of A "needlessly", but this programming pattern is easy for matlab to prove will work without problems.

[Yu Li]

thank you, it works!