Paul : I haven't tested this but try it and let me know. Let x be the # of the col in A and y be the # of the column in B.
colinA<-A[,x] colinB<-B[,y] matchingrows<-B[(colinB %in% colinA),colinB] C<-A[-1.0*c(matchingrows),] I think C should be the resulting matrix that you want but it's untested so check it. I'm notorious for missing unforeseen problems unless I test things. When I have time later tonight, I'll test it myself. Maybe someone else will help you now if it doesn't work so I'll include the list. -----Original Message----- From: H. Paul Benton [mailto:[EMAIL PROTECTED] Sent: Wednesday, November 29, 2006 8:43 PM To: 'jim holtman'; Leeds, Mark (IED) Cc: [email protected] Subject: RE: [R] better define: matrix comparison and cbind issue Ok, so columns are fixed and my apologizes, for the incorrect subscripting. So I have the matching down because I'm matching a number so I've used an if statement with some fuzz. At the moment my code from my earlier post gets me a long vector with the data in it but not a nice matrix that is readable. Also this matrix is only the stuff which was found to be in both A and B. I would like to get A - B as shown before. Cheers, Paul PS. Thx to mark, but don't miss your deadline. ---------- Mark wrote: I understand better now but I just have 1 question and 1 comment. 1) how do you know which columns to compare ? Is that fixed, like parameters x an y where in the case below X = 1 and y = 1 ? Or does it somehow depend on the matrix ? 2) your email was still really confusing because you are subscripting incorrectly when you Refers to rows and columns. You have it backwards : A[1,] is the first row. A[,1] is the first column. -----Original Message----- From: jim holtman [mailto:[EMAIL PROTECTED] Sent: Wednesday, November 29, 2006 2:40 PM To: H. Paul Benton Subject: Re: [R] better define: matrix comparison and cbind issue match(a[9,], b[9,]) will tell you which elements in 'a' match 'b' On 11/29/06, H. Paul Benton <[EMAIL PROTECTED]> wrote: > Hello, > > Sorry to all for the lack of communication, and thanks to those with > the suggestions. > > So I have two matrixes which are different sizes, same column number > but different row number. > > What I would like to do is to compare A to B. In the 6 and 9th column there > are ref numbers (molecular masses to be exact). I would like to check > A and > B by these columns. If I find that the number in A[9,x] and B[9, x] > are the > same then I want to remove the row that it is comparing from A. So overall, > if something appears in B then I remove it from A. > > > > Cheers, > > > > Paul > > > > > > Research Technician > > Mass Spectrometry > > o The > > / > > o Scripps > > \ > > o Research > > / > > o Institute > > > > > [[alternative HTML version deleted]] > > ______________________________________________ > [email protected] 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. > -- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem you are trying to solve? -------------------------------------------------------- This is not an offer (or solicitation of an offer) to buy/se...{{dropped}} ______________________________________________ [email protected] 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.
