Try this: mine <- 1:6 table.combos <- matrix(data = 1:12, nrow = 10, ncol = 6, byrow) row.is.a.match <- apply(table.combos, 1, identical, mine) match.idx <- which(row.is.a.match) total.matches <- sum(row.is.a.match)
On Sat, Jan 28, 2012 at 2:10 AM, Jason J. Pitt <pit...@uchicago.edu> wrote: > > 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. ______________________________________________ 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.
