R: Accurately computes the logarithm of the sum of exponentials...

rowLogSumExps {matrixStats} | R Documentation

## Accurately computes the logarithm of the sum of exponentials across rows or columns

### Description

Accurately computes the logarithm of the sum of exponentials across rows or columns.

### Usage

    rowLogSumExps(lx, rows = NULL, cols = NULL, na.rm = FALSE, dim. = dim(lx), ...)

    colLogSumExps(lx, rows = NULL, cols = NULL, na.rm = FALSE, dim. = dim(lx), ...)

### Arguments

`lx` | A `numeric` NxK `matrix`. Typically `lx` are log(x) values.
`rows` | A `vector` indicating subset of rows to operate over. If `NULL`, no subsetting is done.
`cols` | A `vector` indicating subset of columns to operate over. If `NULL`, no subsetting is done.
`na.rm` | If `TRUE`, missing values are excluded.
`dim.` | An `integer` `vector` of length two specifying the dimension of `x`, also when not a `matrix`. Comment: The reason for this argument being named with a period at the end is purely technical (we get a run-time error if we try to name it `dim`).
`...` | Not used.

### Value

A `numeric` `vector` of length N (K).

### Benchmarking

These methods are implemented in native code and have been optimized for speed and memory.

### Author(s)

Native implementation by Henrik Bengtsson. Original R code by Nakayama ??? (Japan).

### See Also

To calculate the same on vectors, `logSumExp`().

[Package matrixStats version 0.59.0 Index]