colDiffs: Calculates the difference between each element of a row...

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

Description

Calculates the difference between each element of a row (column) of a matrix-like object.

Usage

## S4 method for signature 'DelayedMatrix'
colDiffs(
  x,
  rows = NULL,
  cols = NULL,
  lag = 1L,
  differences = 1L,
  force_block_processing = FALSE,
  ...
)

## S4 method for signature 'DelayedMatrix'
rowDiffs(
  x,
  rows = NULL,
  cols = NULL,
  lag = 1L,
  differences = 1L,
  force_block_processing = FALSE,
  ...
)

Arguments

x	A NxK DelayedMatrix.
rows	A vector indicating the subset of rows (and/or columns) to operate over. If NULL, no subsetting is done.
cols	A vector indicating the subset of rows (and/or columns) to operate over. If NULL, no subsetting is done.
lag	An integer specifying the lag.
differences	An integer specifying the order of difference.
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.

Details

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

Value

Returns a numeric matrix with one column (row) less than x: Nx(K-1) or (N-1)xK.

Author(s)

Peter Hickey

See Also

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

• base::diff().

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))

colDiffs(dm_matrix)

rowDiffs(dm_HDF5)
# In reverse column order
rowDiffs(dm_HDF5, cols = seq(ncol(dm_HDF5), 1, -1))

DelayedMatrixStats documentation built on Feb. 5, 2021, 2:04 a.m.