[R] Count number of rows in a matrix with a character pattern
ruipbarradas at sapo.pt
Mon Apr 30 00:00:13 CEST 2012
Michael Weylandt wrote
> I'd use a combination of rownames(), grepl() and sum().
> Get the names with the first, test with the second and count the positives
> (by coercing TRUE -> 1) with the last
> On Apr 29, 2012, at 3:46 PM, katarv <katiasmirn@> wrote:
>> I have a large data set that I input as a matrix, where I have 1:x rows
>> with names AX, then x+1: y rows named AY, etc. The idea is that I have
>> count how many rows exactly I have with name AX and how many I have with
>> name AY (or find which row numbers have names AX). Is there any way in R
>> count a number of rows with a name matching a required pattern?
>> Thanks in advance,
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Misread the op. Didn't see 'count', my code gives where, not how many.
So the corrected version shoulld be
View this message in context: http://r.789695.n4.nabble.com/Count-number-of-rows-in-a-matrix-with-a-character-pattern-tp4596848p4597035.html
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