indexByRow {matrixStats}R Documentation

Translates matrix indices by rows into indices by columns

Description

Translates matrix indices by rows into indices by columns.

Usage

 indexByRow(x, idxs=NULL, ...)

Arguments

x A matrix.
idxs A vector of indices. If NULL, all indices are returned.
... Not use.

Value

Returns an integer vector of indices.

Author(s)

Henrik Bengtsson (http://www.braju.com/R/)

Examples

 x <- matrix(NA, nrow=5, ncol=4)
 y <- t(x)
 idxs <- seq(along=x)

 # Assign by columns
 x[idxs] <- idxs
 print(x)

 # Assign by rows
 y[indexByRow(y, idxs)] <- idxs
 print(y)

 stopifnot(x == t(y))

[Package matrixStats version 0.1.6 Index]