colVars: Calculates the variance for each row (column) of a...

In PeteHaitch/DelayedMatrixStats: Functions that Apply to Rows and Columns of 'DelayedMatrix' Objects

Calculates the variance for each row (column) of a matrix-like object

Description

Calculates the variance for each row (column) of a matrix-like object.

Usage

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

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

Arguments

x	A NxK DelayedMatrix.
rows, cols	A vector indicating the subset of rows (and/or columns) to operate over. If NULL, no subsetting is done.
na.rm	If TRUE, missing values (NA or NaN) are omitted from the calculations.
center	(optional) the center, defaults to the row means.
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 ⁠\link[DelayedArray]{getAutoBlockSize}()⁠) columns (colFoo()) or rows (rowFoo()) into memory as an ordinary base::array.
...	Additional arguments passed to specific methods.
useNames	If TRUE (default), names attributes of result are set. Else if FALSE, no naming support is done.

Details

The S4 methods for x of type matrix, array, table, or numeric call matrixStats::rowVars / matrixStats::colVars.

Value

Returns a numeric vector of length N (K).

Author(s)

Peter Hickey

See Also

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

• For mean estimates, see rowMeans2() and rowMeans().

• For standard deviation estimates, see rowSds().

• stats::var().

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)

PeteHaitch/DelayedMatrixStats documentation built on Nov. 9, 2024, 10:53 a.m.