[EMAIL PROTECTED] >> y <- matrix(1:8, ncol=2) >> is.matrix(y[-c(1,2),]) >[1] TRUE >> is.matrix(y[-c(1,2,3),]) >[1] FALSE >> is.matrix(y[-c(1,2,3,4),]) >[1] TRUE
>It seems like an inconsistent behaviour: >- with 2 or more rows we have a matrix >- with 1 row we do not have a matrix and >- with 0 rows we have a matrix again ?'[' explains it. Using your example: > is.matrix(y[-c(1, 2), , drop=FALSE]) [1] TRUE > is.matrix(y[-c(1, 2, 3), , drop=FALSE]) [1] TRUE > is.matrix(y[-c(1, 2, 3, 4), , drop=FALSE]) [1] TRUE -- François Pinard http://pinard.progiciels-bpi.ca ______________________________________________ [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
