Question

I have a vector filter and I need to use the vector element index-number within the filter.
What would the syntax be for the INDEXNUMBER in the below example?

myVector(myVector < 0.05*(INDEXNUMBER/(120-INDEXNUMBER)));

Thanks,

Answer 1

Assuming I understand what you’re trying to do, you would just substitute myVector for INDEXNUMBER:

myVector  = rand(1,10);
selection = myVector(myVector < 0.05*(myVector/(120-myVector)));

The logical indexing (the part inside the outermost parenthesis, second line) is simply doing a logical comparison on all elements of myVector, returning an equal length vector of 0‘s and 1‘s, and the selecting the elements of myVector which correspond to the 1‘s. If this isn’t what you’re doing, just make sure that your dimensions work out correctly (size of left hand inequality == size of right hand inequality == size of variable being selected) and all should be well.

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To use the position of each number, you could use the following:

myVector  = rand(1,10);
indices   = 1:length(myVector);
selection = myVector(myVector < 0.05*(indices/(120-indices)));