Hi, One way would be: which(apply(t(B),1,paste,collapse="")%in%apply(t(A),1,paste,collapse="")) #[1] 105 196 274 340 395 B[,105] #[1] 1 15 16 B[,196] #[1] 2 15 16 B1<-B[,!apply(t(B),1,paste,collapse="")%in%apply(t(A),1,paste,collapse="")] dim(B1) #[1] 3 555 dim(B) #[1] 3 560
#or B2<-B[,is.na(match(interaction(as.data.frame(t(B))),interaction(as.data.frame(t(A)))))] identical(B1,B2) #[1] TRUE A.K. ----- Original Message ----- From: Thiem Alrik <th...@sipo.gess.ethz.ch> To: "mailman, r-help" <r-help@r-project.org> Cc: Sent: Saturday, July 13, 2013 9:45 AM Subject: [R] Test for column equality across matrices Dear list, I have two matrices A <- matrix(t(expand.grid(c(1,2,3,4,5), 15, 16)), nrow = 3) B <- combn(16, 3) Now I would like to exclude all columns from the 560 columns in B which are identical to any 1 of the 6 columns in A. How could I do this? Many thanks and best wishes, Alrik ______________________________________________ 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.
