Date: Apr 29, 2013 3:54 PM
Author: Derek Goring
Subject: Re: Collapse/Compress Long-form Data

On Tuesday, April 30, 2013 7:39:09 AM UTC+12, Cory  wrote:
> Hi MATLABers,
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> I have some data that can be put into groups of different sizes. For instances, I might have an nX2 vector where the first column is a group number and the second is a value:
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> [1 2; 1 3; 1 1; 2 6; 2 10; 3 9; 3 11; 3 0]
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> Is there an easy/fast/vectorized way to get MATLAB to take the minimum (maximum, sum, mean...) by group number? For the minimum, e.g, the result would be:
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> [1 1; 2 6; 3 0]
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> Obviously I could use loops, but I'm curious if there's a better solution. Thanks!
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> Cory


Loop on group number, and calculate stats using vectorised code.