MATLAB: Parfor loop variable cannot be classified

classifiedparforsplicevariable

Hi all,
I'm just not quite clear why this won't work, or what I can do to fix it.
I get the error
Error: File: LabTracker_Serial_Parralel.m Line: 105 Column: 5
The variable microMovie in a parfor cannot be classified.
See Parallel for Loops in MATLAB, "Overview".
But it would seem to me like each loop is independent of the others. So shouldn't parfor be suitable here?
Any thoughts? Thank you
Here is the code,
microMovie = zeros(NumberOfTargets * pointsToSave, 3, numFrames);
parfor i = 1: numFrames
     [sortedValues,sortIndex] = sort(ghostFrame(:),'descend');
      maxIndex = sortIndex(1:NumberOfFlies * pointsToSave);
      [rowsub, colsub] = ind2sub([size(ghostFrame,1) size(ghostFrame,2)], maxIndex);
      microMovie(:,1,i) = rowsub;
      microMovie(:,2,i) = colsub;
      microMovie(:,3,i) = movieFrame(maxIndex);
end
save('microMovie');

Best Answer

The parfor variable classificiation is getting confused by the type of indexing you are performing with the microMovie variable. You can work around this by creating a temporary variable.
parfor i = 1: numFrames
   [sortedValues,sortIndex] = sort(ghostFrame(:),'descend');
    maxIndex = sortIndex(1:NumberOfFlies * pointsToSave);
    [rowsub, colsub] = ind2sub([size(ghostFrame,1) size(ghostFrame,2)], maxIndex);
      % start of modified code
      temp = zeros(NumberOfTargets*pointsToSave,3);
      temp(:,1) = rowsub;
      temp(:,2) = colsub;
      temp(:,3) = movieFrame(maxIndex);
      microMovie(:,:,i) = temp;
  end
Related Question