Hi Melissa, Well, assuming you know the length of the length of the row in the matrix and vector are the same... if you need a quick fix you could use
mine <- 1:6 table.combos <- matrix(data = 1:12, nrow = 2, ncol = 6, byrow = T) sum(mine == table.combos[1, ]) == length(mine) # returns TRUE sum(mine == table.combos[2, ]) == length(mine) #returns FALSE Though I'm sure there are more elegant and less error prone (if you don't know the lengths are equal) ways of doing this and others will point you in the right direction. Jason ---- Original message ---- >Date: Fri, 27 Jan 2012 17:39:05 -0800 (PST) >From: r-help-boun...@r-project.org (on behalf of Melrose2012 <melissa.patric...@stonybrook.edu>) >Subject: [R] finding rows in a matrix that match a vector >To: r-help@r-project.org > >Hi, > >Please excuse my ignorance, but I am just learning R (this is my very first >day programming in R) and having a really hard time figuring out how to do >the following: > >I have a matrix that is 1000 row by 6 columns (named 'table.combos') and a 1 >row by 6 column vector (named 'mine'). I want to find every row in >'table.combos' that equals 'mine' and then count this number of times that >this is the case. > >In matlab, I would use the 'find' command but I can not seem to figure out >what syntax to use for R. > >Can anyone please help? > >Again, I'm assuming this is probably a very easy thing to do, but since I am >new to R, I am having a hard time figuring it out. I did some research on >previous posts and saw that the 'apply' function appears to do osmething >like this, except I don't know what function I am supposed to input into >'apply' to use this. > >Thanks in advance for the help! > >Cheers, >Melissa > >-- >View this message in context: http://r.789695.n4.nabble.com/finding-rows-in-a-matrix-that- match-a-vector-tp4335216p4335216.html >Sent from the R help mailing list archive at Nabble.com. > >______________________________________________ >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.
