colCollapse,xgCMatrix-method {sparseMatrixStats}R Documentation

Extract one cell from each row (column) of a matrix-like object

Description

Extract one cell from each row (column) of a matrix-like object.

Usage

## S4 method for signature 'xgCMatrix'
colCollapse(x, idxs, cols = NULL, useNames = NA)

## S4 method for signature 'xgCMatrix'
rowCollapse(x, idxs, rows = NULL, useNames = NA)

Arguments

x

An NxK matrix-like object.

idxs

An index vector with the position to extract. It is recycled to match the number of rows (column)

cols

A vector indicating the subset of rows (and/or columns) to operate over. If NULL, no subsetting is done.

useNames

If NA, the default behavior of the function about naming support is remained. If FALSE, no naming support is done. Else if TRUE, names attributes of result are set.

rows

A vector indicating the subset of rows (and/or columns) to operate over. If NULL, no subsetting is done.

Details

The S4 methods for x of type matrix, array, or numeric call matrixStats::rowCollapse / matrixStats::colCollapse.

Value

Returns a numeric vector of length N (K).

See Also

Examples

mat <- matrix(rnorm(15), nrow = 5, ncol = 3)
  mat[2, 1] <- NA
  mat[3, 3] <- Inf
  mat[4, 1] <- 0

  print(mat)

  rowCollapse(mat, idxs = 2)
  rowCollapse(mat, idxs = c(1,1,2,3,2))

  colCollapse (mat, idxs = 4)

[Package sparseMatrixStats version 1.4.2 Index]