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Subscript indices must either be real positive integers or logicals in bsxfun

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Matthew Zelko
Matthew Zelko on 19 Jan 2016
Commented: Guillaume on 19 Jan 2016
Hi there,
Had a look at various others posts that include this error message but cannot find what is missing from my code. Feel like I am brute forcing this by as it stands I have
T 19081 x 22 double % Raw Data values
StdTimedEdit 1 x 22 double % Standard Deviation values for each column
MeanTimedEdit 1 x 22 double % Means for each column
StDIndexFull 19081 x 22 logical % Logical Index for which values I want to run the bxs function on
I am trying to do run a bxsfun to replace values outside 2 standard deviations from the mean for each column with 'NaN', but only on the values that equal 1 in the logical StDIndexFull. Currently it looks as such:
T(bsxfun(@lt, T(T(StdIndexFull)), (MeanTimedEdit + 2*StDsTimedEdit)) ...
& bsxfun(@gt, T(T(StdIndexFull)), (MeanTimedEdit - 2*StDsTimedEdit)))= NaN;
This returns the following error:
Subscript indices must either be real positive integers or logicals.
Any assistance or opinions would be muchly appreciated
Matt

Accepted Answer

Guillaume
Guillaume on 19 Jan 2016
Edited: Guillaume on 19 Jan 2016
As Star said, one of your problem is the use of T to index into itself. That makes no sense, I'm not sure what you intended with that.
In addition, your logic has gone a bit wrong on where to use the logical array. You want to find the values that:
  1. are outside the standard deviation (using bsxfun indeed) AND
  2. correspond to true in the logical array
This is written as:
(bsxfun(@lt, T, MeanTimedEdit - 2*StDsTimedEdit) | bsxfun(@gt, T, MeanTimedEdit + 2*StDsTimedEdit)) ... %part 1
& StdIndexFull %part 2
So the replacing is written as:
T((bsxfun(@lt, T, MeanTimedEdit - 2*StDsTimedEdit) | bsxfun(@gt, T, MeanTimedEdit + 2*StDsTimedEdit)) & StdIndexFull) = nan;
  2 Comments
Guillaume
Guillaume on 19 Jan 2016
Sorry about the typo, now fixed.
No, bsxfun is not using the index as a stand alone criteria. What is happening is that the two bsxfun are generating a logical array telling you which number is outside the standard deviation (step 1). It does not use your index array at all. That step 1 logical array is then combined with your index logical array using normal boolean operation.

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