colDiffs,DelayedMatrix-method {DelayedMatrixStats}

R Documentation

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

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,
  ...,
  useNames = NA
)

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

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.
useNames	If NA, the default behavior of the function about naming support is remained. If FALSE, no naming support is done. Else if TRUE, names attributes of result are set. Only useNames = NA is currently supported, other values are silently ignored.

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))

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