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

In sparseMatrixStats: Summary Statistics for Rows and Columns of Sparse Matrices

Description

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

Usage

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

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

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.
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

• 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)

sparseMatrixStats documentation built on Feb. 4, 2021, 2 a.m.