I think this sounds right, Cole. With the square pulse in the list being the same duration as the kernel, the max will occur when the correlation has lined up the kernel with the pulse in the list. Since we are indexing to the 1st position in the kernel, the index of the correlation is at the 1st position of the pulse when they are aligned, so the max occurs at the position of the leading edge of the pulse in the list. (With the 1st position index, there is no overhang of the kernel on the left of the list, so we would not need padding to preserve this -- the result is shortened from the right only.)

With alignment to the middle position of the kernel, the max occurs when the index is at the center of the pulse in the list. but if we want positions in the result to correspond to the positions in the list we do need padding to lengthen the list on the left before correlation, so we don't shorten the result on the left.

Best, David

Thanks for the reply. You are correct that in this example it returns the expected result. I am at a loss for why it does not give the desire outcome with my larger data sets.

I have uploaded the full length data sets if anyone is willing to run the data.

As you can see from the uploaded image above the peak from the correlation is located at the beginning of the square pulse instead of the middle. I am confident it should be in the middle. In principle this larger data sets are a high res case of the previous example.

Thanks

Attachments:

I have tried:

ListCorrelate[ideal, test]

and

ListCorrelate[ideal, test,-1]

and

ListCorrelate[ideal, test,{-1,1},0].

None have worked.

Cole,

You are more likely to get a useful response if you post usable code. Please see: How to post

Kind regards, David