which(x>0) or
which(x>0, arr.ind=TRUE) depending on your application. Michael On Feb 13, 2012, at 5:38 PM, Sam Steingold <s...@gnu.org> wrote: > if I have a vector, I can find the indexes which satisfy a condition: > x <- rnorm(10) > [1] 0.4751132 -0.5442322 -0.1979854 -0.2455521 0.8349336 -0.4283345 > [7] 0.6108130 2.0576160 1.1251716 -1.3933637 > x[x>0] > [1] 0.4751132 0.8349336 0.6108130 2.0576160 1.1251716 > (1:10)[x>0] > [1] 1 5 7 8 9 > > how about a matrix? > > 00000G 00000Q 00002O 000035 000037 00003A > 00000G NA 0.008226002 0.005631718 0.0002625585 0.0010673235 0.0045310915 > 00000Q NA NA 0.003714951 0.0002007877 0.0016983426 0.0011083925 > 00002O NA NA NA 0.0024233691 0.0069849678 0.0024510792 > 000035 NA NA NA NA 0.0006499707 0.0008420414 > 000037 NA NA NA NA NA 0.0005448872 > 00003A NA NA NA NA NA NA > 00003B NA NA NA NA NA NA > 00003G NA NA NA NA NA NA > 00003H NA NA NA NA NA NA > 00003I NA NA NA NA NA NA > 00003B 00003G 00003H 00003I > 00000G 0.0007254316 0.0093954826 3.420231e-04 0.003974556 > 00000Q 0.0013883606 0.0019778247 3.609791e-05 0.001552725 > 00002O 0.0027340806 0.0082790646 2.561862e-03 0.012297821 > 000035 0.0006025767 0.0004534397 1.053946e-03 0.001681780 > 000037 0.0005501974 0.0021137871 1.733880e-03 0.003712675 > 00003A 0.0008969849 0.0043855527 2.786194e-06 0.002492954 > 00003B NA 0.0019791290 8.301787e-04 0.002816774 > 00003G NA NA 3.181892e-07 0.010608717 > 00003H NA NA NA 0.001066141 > 00003I NA NA NA NA > > how do I find the cells whose values are, e.g., > 0.01 ?? > > thanks! > > -- > Sam Steingold (http://sds.podval.org/) on Ubuntu 11.10 (oneiric) X > 11.0.11004000 > http://www.childpsy.net/ http://pmw.org.il http://americancensorship.org > http://ffii.org http://iris.org.il http://truepeace.org http://dhimmi.com > The difference between genius and stupidity is that genius has its limits. > > ______________________________________________ > 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.