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 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).

See Also

See rowMeans() in colSums().

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 1.4.0 Index]