For that, it is more straightforward to use which(M==1, arr.ind=TRUE)
However, the desired output has 8 indices, not 12. I don't see what the desired pattern is... - pd > On 11 Jun 2020, at 03:01 , Jeff Newmiller <jdnew...@dcn.davis.ca.us> wrote: > > M <- matrix(c(2,2,rep(1,12), 2), nrow = 5,byrow = FALSE) > ix <- expand.grid( r = seq.int( nrow( M ) ) > , c = seq.int( ncol( M ) ) > ) > ix[ 1 == c(M), ] > > > On June 10, 2020 5:29:10 PM PDT, Jinsong Zhao <jsz...@yeah.net> wrote: >> Hi there, >> >> I have a matrix similar as: >> >> M <- matrix(c(2,2,rep(1,12), 2), nrow = 5,byrow = FALSE) >> >> I hope to get the border subscript of the block with value 1. In the >> above example, I hope to get: >> >> (3,1), (5,1), (5,2), (4,2), (4,3), (1,3), (1,2), (3,2) >> >> Is there any function can do that? or any implement idea? Thanks! >> >> Best, >> Jinsong >> >> ______________________________________________ >> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see >> 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. > > -- > Sent from my phone. Please excuse my brevity. > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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. -- Peter Dalgaard, Professor, Center for Statistics, Copenhagen Business School Solbjerg Plads 3, 2000 Frederiksberg, Denmark Phone: (+45)38153501 Office: A 4.23 Email: pd....@cbs.dk Priv: pda...@gmail.com ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.
