On 11/3/06, Waverley <[EMAIL PROTECTED]> wrote: > Hi, > For example: > > > a = matrix (12, 3, 4) > > b = a[1,] > > b > [1] 12 12 12 12 >
It doesn't have anything to do with one-row matrices, at least in your example, since that isn't what you made. Instead, you created a matrix with 3 rows, 4 columns, and all values equal to 12. > a <- matrix(12, 3, 4) > a [,1] [,2] [,3] [,4] [1,] 12 12 12 12 [2,] 12 12 12 12 [3,] 12 12 12 12 > a[1,] [1] 12 12 12 12 You probably intended > a <- matrix(c(12, 3, 4), nrow=1) > a [,1] [,2] [,3] [1,] 12 3 4 But to solve what I think you were actually asking, even though it wasn't reflected in your example... By default, R drops unused dimensions when subsetting. You can override this behavior > b <- a[1, ,drop=FALSE] > b [,1] [,2] [,3] [1,] 12 3 4 See: ?subset help('[') ?matrix Sarah -- Sarah Goslee http://www.functionaldiversity.org ______________________________________________ R-help@stat.math.ethz.ch 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.