[<--methods {Matrix} | R Documentation |
Methods for "[<-"
, i.e., extraction or subsetting mostly of
matrices, in package Matrix.
There are more than these:
[-methods
for subsetting "Matrix"
objects; the
index
class;
Extract
about the standard subset assignment (and extraction).
(m <- Matrix(round(rnorm(7*4),2), nrow = 7)) stopifnot(identical(m, m[])) m[2, 3] # simple number m[2, 3:4] # simple numeric of length 2 m[2, 3:4, drop=FALSE] # sub matrix of class 'dgeMatrix' m[-(4:7), 3:4] # dito; the upper right corner of 'm' ## rows or columns only: m[1,] # first row, as simple numeric vector m[,2] # 2nd column m[,1:2] # sub matrix of first two columns m[-(1:6),, drop=FALSE] # not the first 6 rows, i.e. only the 7th