On Tue, Jun 30, 2009 at 9:19 AM, Rainer M Krug<r.m.k...@gmail.com> wrote: > Hi > > imagine the following situation: > > a <- runif(100) > plot(a[a>0.5]) > > plots only the elements in the vector which are larger then 0.5 > > Now imagine a matrix: > > b <- matrix(runif(20000), ncol=40, nrow=50) > image(b[b>0.5]) > Error in image.default(b[b > 0.5]) : argument must be matrix-like > > Is there a similar way then above to plot an image from the matrix with only > the elements larger then 0.5, and the remaining elements equals NA? > > I know I could do something like > > image(b, zlim=c(0.5, 1)) > but this includes 0.5 in the image, > > bb <- b > bb[bb<=0.5] <- NA > image(bb) > > but this includes an additional assignment.
Although this does involve an assignment underneath as well perhaps its sufficient for your purposes: image(replace(b, b <= 0.5, NA)) ______________________________________________ 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.