R: Accurately calculates the logarithm of the sum of...

colLogSumExps,xgCMatrix-method {sparseMatrixStats}

R Documentation

Accurately calculates the logarithm of the sum of exponentials for each row (column) of a matrix-like object

Description

Accurately calculates the logarithm of the sum of exponentials for each row (column) of a matrix-like object.

Usage

## S4 method for signature 'xgCMatrix'
colLogSumExps(lx, rows = NULL, cols = NULL, na.rm = FALSE)

## S4 method for signature 'xgCMatrix'
rowLogSumExps(lx, rows = NULL, cols = NULL, na.rm = FALSE)

Arguments

`lx`	An NxK matrix-like object. Typically `lx` are `log(x)` values.
`rows`	A `vector` indicating the subset (and/or columns) to operate over. If `NULL`, no subsetting is done.
`cols`	A `vector` indicating the subset (and/or columns) to operate over. If `NULL`, no subsetting is done.
`na.rm`	If `TRUE`, `NA`s are excluded first, otherwise not.

Details

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

Value

Returns a numeric vector of length N (K).

Examples

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

[Package sparseMatrixStats version 1.2.1 Index]