colCollapse-xgCMatrix-method: Extract one cell from each row (column) of a matrix-like...

colCollapse,xgCMatrix-methodR 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 = TRUE)

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

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)

useNames

If TRUE (default), names attributes of result are set. Else if FALSE, no naming support is done.

rows, cols

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, table, or numeric call matrixStats::rowCollapse / matrixStats::colCollapse.

Value

Returns a numeric vector of length N (K).

See Also

  • matrixStats::rowCollapse() and matrixStats::colCollapse() which are used when the input is a matrix or numeric vector.

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)

const-ae/sparseMatrixStats documentation built on June 15, 2024, 9:36 a.m.