Thanks, that solved the problem! - Moises
-----Original Message----- From: Roger D. Peng [mailto:[EMAIL PROTECTED] Sent: Sunday, August 29, 2004 3:08 PM To: Moises Hassan Cc: R Help Subject: Re: [R] removing invariant columns from a matrix See question 7.7 in the R FAQ (http://cran.r-project.org/doc/FAQ/R-FAQ.html) -roger Moises Hassan wrote: > It works great, except that in the case where only one column is left, > it returns a vector and the column name is lost. How can you avoid that > behavior? > > Thanks, > - Moises > > > -----Original Message----- > From: Spencer Graves [mailto:[EMAIL PROTECTED] > Sent: Saturday, August 28, 2004 8:26 PM > To: Peter Dalgaard > Cc: Moises Hassan; R Help > Subject: Re: [R] removing invariant columns from a matrix > > Both the previous solutions seem to assume a numeric matrix. How > about the following: > > A <- array(letters[c(rep(1, 13), rep(2, 13), 1:26)], dim=c(13, 5)) > A[, apply(A, 2, function(x)any(x[-1] != x[-length(x)]))] > A[, apply(A, 2, function(x)any(x[-1] != x[-length(x)])] > > enjoy. spencer graves > > Peter Dalgaard wrote: > > >>"Moises Hassan" <[EMAIL PROTECTED]> writes: >> >> >> >> >>>I'm looking for an efficient way of removing zero-variance columns > > from > >>>a large matrix. >>> >>>Any suggestions? >>> >>> >> >>A[,apply(A,2,var)>0] >> >> >> > > > ______________________________________________ > [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 > ______________________________________________ [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
