# col

0th

Percentile

##### Column Indexes

Returns a matrix of integers indicating their column number in a matrix-like object, or a factor of column labels.

Keywords
array
##### Usage
col(x, as.factor = FALSE)
.col(dim)
##### Arguments
x

a matrix-like object, that is one with a two-dimensional dim.

dim

a matrix dimension, i.e., an integer valued numeric vector of length two (with non-negative entries).

as.factor

a logical value indicating whether the value should be returned as a factor of column labels (created if necessary) rather than as numbers.

##### Value

An integer (or factor) matrix with the same dimensions as x and whose ij-th element is equal to j (or the j-th column label).

##### References

Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.

row to get rows; slice.index for a general way to get slice indices in an array.
library(base) # NOT RUN { # extract an off-diagonal of a matrix ma <- matrix(1:12, 3, 4) ma[row(ma) == col(ma) + 1] # create an identity 5-by-5 matrix more slowly than diag(n = 5): x <- matrix(0, nrow = 5, ncol = 5) x[row(x) == col(x)] <- 1 (i34 <- .col(3:4)) stopifnot(identical(i34, .col(c(3,4)))) # 'dim' maybe "double" # }