R: Calculates difference for each row (column) in a matrix

colDiffs {DelayedMatrixStats}

R Documentation

Calculates difference for each row (column) in a matrix

Description

Calculates difference for each row (column) in a matrix.

Usage

colDiffs(
  x,
  rows = NULL,
  cols = NULL,
  lag = 1L,
  differences = 1L,
  dim. = dim(x),
  ...
)

rowDiffs(
  x,
  rows = NULL,
  cols = NULL,
  lag = 1L,
  differences = 1L,
  dim. = dim(x),
  ...
)

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

## S4 method for signature 'DelayedMatrix'
rowDiffs(
  x,
  rows = NULL,
  cols = NULL,
  lag = 1L,
  differences = 1L,
  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.
`lag`	An `integer` specifying the lag.
`differences`	An `integer` specifying the order of difference.
`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 `\link[DelayedArray]{getAutoBlockSize}()`) columns (`colFoo()`) or rows (`rowFoo()`) into memory as an ordinary base::array.

Value

Returns a numeric Nx(K-1) or (N-1)xK matrix.

Author(s)

Peter Hickey

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))

[Package DelayedMatrixStats version 1.10.1 Index]