How fast is matlab find

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Toggle Main Navigation. Search MathWorks. Open Mobile Search. Trial software. Problem Like 3. Solve Later. High performance methods don't appear to incur any increased processing time. Richard Brown on 3 May More Answers 6.

Andrei Bobrov on 3 May Vote 1. Hi Richard! I agree with you. Vote 0. Depending on whether you want the first or the last occurence. Leah on 2 May Matlab has a nice function built in for this. Walter Roberson on 2 May Your suggested code will not work if there are any duplicates, as the find would return multiple values in that case and multiple values cannot be stored into a single numeric array element. Have you considered using the second or third return value from unique?

Thanks guys -- forgot to mention that I need to find the indices for all of the elements if there are multiple occurrences. So simply using "unique" doesn't seem to work. Any other thoughts? Oleg Komarov on 2 May A and J will give you what you want. Not really - J is just A : , but with the unique elements replaced with 1:nUnique.

So it's no better. Geoff on 2 May This comes straight out of some of my own code I guess it's the reverse of what you want though. For every element in M , it gives an index into uM. I use this to reduce columns of data in a matrix that are common to multiple targets.

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Is there a faster alternative for find operation? Show older comments. Amulya NV on 13 Sep Vote 0. Edited: Amulya NV on 14 Sep Accepted Answer: Guillaume. I have two large vectors X and Y holding indices.

Lets say. I could do that with the use of find as follows. In spite of using parfor, it it still taking a lot of time. Please help me if there is a faster way to achieve this. Cedric Wannaz on 13 Sep Cancel Copy to Clipboard. Why not two 1D cell arrays? Are a and b always in ranges 1:N and 1:M or can they be more arbitrary sets?