Hi,
dat1$colIndex<-apply(dat1,1,function(x) match(max(x),x)) dat1 # v1 v2 v3 v4 max colIndex #1 0 0 1 2 2 4 #2 0 1 2 0 2 3 #3 1 2 3 4 4 4 A.K. ----- Original Message ----- From: Camilo Mora <cm...@dal.ca> To: r-help@r-project.org Cc: Sent: Saturday, June 8, 2013 8:14 PM Subject: [R] get column index with match using apply Hi everyone, This is probably something very simple but I have just not been able to figure it out and wonder if perhaps you may know. I want to get the column index in which a given value is found. Values to match are found in the last column of the dataframe. for instance dt= v1 v2 v3 v4 max 0 0 1 2 2 0 1 2 0 2 1 2 3 4 4 expected output: v1 v2 v3 v4 max colIndex 0 0 1 2 2 4 0 1 2 0 2 3 1 2 3 4 4 4 I am using: apply(dt, 1, function(x) match(max,x)) but there is an error in setting "max" in match to be dynamic for each row. I have play around with different configurations and google it with no success. Any input will be greatly appreciated, best, Camilo Camilo Mora, Ph.D. Department of Geography, University of Hawaii Currently available in Colombia Phone: Country code: 57 Provider code: 313 Phone 776 2282 From the USA or Canada you have to dial 011 57 313 776 2282 http://www.soc.hawaii.edu/mora/ ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
