colLogSumExps-xgCMatrix-method: Accurately calculates the logarithm of the sum of...

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

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, NAs 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).

See Also

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

• rowSums2()

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)

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