colVars {DelayedMatrixStats}R Documentation

Variance estimates for each row (column) in a matrix

Description

Variance estimates for each row (column) in a matrix.

Usage

colVars(x, rows = NULL, cols = NULL, na.rm = FALSE, center = NULL,
  dim. = dim(x), ...)

rowVars(x, rows = NULL, cols = NULL, na.rm = FALSE, center = NULL,
  dim. = dim(x), ...)

## S4 method for signature 'DelayedMatrix'
colVars(x, rows = NULL, cols = NULL,
  na.rm = FALSE, center = NULL, dim. = dim(x),
  force_block_processing = FALSE, ...)

## S4 method for signature 'DelayedMatrix'
rowVars(x, rows = NULL, cols = NULL,
  na.rm = FALSE, center = NULL, dim. = dim(x),
  force_block_processing = FALSE, ...)

Arguments

x

A NxK DelayedMatrix.

rows

A vector indicating subset of rows (and/or columns) to operate over. If NULL, no subsetting is done.

cols

A vector indicating subset of rows (and/or columns) to operate over. If NULL, no subsetting is done.

na.rm

If TRUE, missing values are excluded first, otherwise not.

center

(optional) The center, defaults to the row means.

dim.

An integer vector of length two specifying the dimension of x, also when not a matrix.

...

Additional arguments passed to specific methods.

force_block_processing

FALSE (the default) means that a seed-aware, optimised method is used (if available). This can be overridden to use the general block-processing strategy by setting this to TRUE (typically not advised). The block-processing strategy loads one or more (depending on getOption("DelayedArray.block.size")) columns (colFoo()) or rows (rowFoo()) into memory as an ordinary base::array.

Value

Returns a numeric vector of length N (K).

See Also

See rowMeans() and rowSums() in colSums().

Examples

# A DelayedMatrix with a 'matrix' seed
dm_matrix <- DelayedArray(matrix(c(rep(1L, 5),
                                   as.integer((0:4) ^ 2),
                                   seq(-5L, -1L, 1L)),
                                 ncol = 3))
# A DelayedMatrix with a 'HDF5ArraySeed' seed
# NOTE: Requires that the HDF5Array package is installed
library(HDF5Array)
dm_HDF5 <- writeHDF5Array(matrix(c(rep(1L, 5),
                                   as.integer((0:4) ^ 2),
                                   seq(-5L, -1L, 1L)),
                                 ncol = 3))

colVars(dm_matrix)

rowVars(dm_matrix)
[Package DelayedMatrixStats version 1.2.0 Index]