R: Gets an order statistic for each row (column) in a matrix

colOrderStats {DelayedMatrixStats}

R Documentation

Gets an order statistic for each row (column) in a matrix

Description

Gets an order statistic for each row (column) in a matrix.

Usage

colOrderStats(x, rows = NULL, cols = NULL, which, dim. = dim(x), ...)

rowOrderStats(x, rows = NULL, cols = NULL, which, dim. = dim(x), ...)

## S4 method for signature 'DelayedMatrix'
colOrderStats(
  x,
  rows = NULL,
  cols = NULL,
  which,
  dim. = dim(x),
  force_block_processing = FALSE,
  ...
)

## S4 method for signature 'DelayedMatrix'
rowOrderStats(
  x,
  rows = NULL,
  cols = NULL,
  which,
  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.
`which`	An `integer` index in [1,K] ([1,N]) indicating which order statistic to be returned.
`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.

Details

The implementation of rowOrderStats() is optimized for both speed and memory. To avoid coercing to doubles (and hence memory allocation), there is a unique implementation for integer matrices.

Value

Returns a numeric vector of length N (K).

Missing values

This method does not handle missing values, that is, the result corresponds to having na.rm = FALSE (if such an argument would be available).

Author(s)

Peter Hickey

Examples

# A DelayedMatrix with a 'Matrix' seed
dm_Matrix <- DelayedArray(Matrix::Matrix(c(rep(1L, 5),
                                           as.integer((0:4) ^ 2),
                                           seq(-5L, -1L, 1L)),
                                         ncol = 3))
# Only using columns 2-3
colOrderStats(dm_Matrix, cols = 2:3, which = 1)

# Different algorithms, specified by `which`, may give different results
rowOrderStats(dm_Matrix, which = 1)
rowOrderStats(dm_Matrix, which = 2)

[Package DelayedMatrixStats version 1.10.1 Index]