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Extracting common values and there indices from two waves

Wed, 01/06/2021 - 01:30 am

I have two waves of different dimensions. Both these have few overlapping/same values but at different locations .e.g., the 4^th index of wave 1 might be the same as the 6^th index of wave 2, etc.I am looking to extract these common values from 2 waves and also the indices where they lie on the larger waves. Do you have any suggestions on how can I do that? I tried functions like binary search or find value but they don’t seem to do the desired job

chozo

A surefire but slow way to do this is to loop over the smaller wave and check whether each point gives any result with FindValue applied on the larger wave. If V_value is different from -1 note both the position and the current search value in a separate result wave.

January 6, 2021 at 02:20 am - Permalink

KurtB

You can use Extract with the /INDX flag, searching for each value in your smaller wave one at a time.

As an example, try this:

Function doStuff()

    Make/O/I myData = {1,4,6,2,4,3,2,6,5,2}

    Make/O/I mySearch = {4,2}

    Make/O/I/N=0 myResult

    variable i

    Make/FREE/I myTempResult

    for(i = 0; i < DimSize(mySearch, 0); i += 1)

        Extract/FREE/INDX myData, myTempResult, myData==mySearch[i]

        Concatenate  {myTempResult}, myResult

    endfor

End

You can easily extend this to give the matching value as well.

January 6, 2021 at 03:06 am - Permalink