> -----Original Message----- > From: r-help-boun...@r-project.org > [mailto:r-help-boun...@r-project.org] On Behalf Of Murat Tasan > Sent: Sunday, September 27, 2009 3:59 PM > To: r-help@r-project.org > Subject: [R] dimension-preserving matrix coersion > > i've written a function to coerce a matrix (e.g. from numeric to > logical), but i'd like to know if someone has a more elegant method > for this: > > > m <- matrix(c(0, 1, 1, 0), ncol = 2) > > m <- as.logical(m) > > m > [1] FALSE TRUE TRUE FALSE > > i'd like 'm' to still be a matrix with the original dimensions. in my > function to do this, i coerce 'm' to a logical, then re-form it as a > matrix, which seems like an extra (possibly bug-introducing) step that > might be avoided if i knew of some "hidden" feature that might permit > this in one fell swoop.
m <- m != 0 will do it, as will mode(m) <- "logical" The former has the advantage that you don't have to use the canonical mapping of 0<->FALSE,anything else<->TRUE, but can use any standard comparison or vectorized logical operator. It also seems cleaner in that it can be used inside a larger expression, like m[m!=0]. Bill Dunlap TIBCO Software Inc - Spotfire Division wdunlap tibco.com > > any ideas? > > ______________________________________________ > 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.
