R: Gets the rank of each row (column) of a matrix

rowRanks {matrixStats}

R Documentation

Gets the rank of each row (column) of a matrix

Description

Gets the rank of each row (column) of a matrix.

Usage

rowRanks(x, rows = NULL, cols = NULL, ties.method = c("max", "average",
  "min"), dim. = dim(x), ...)

colRanks(x, rows = NULL, cols = NULL, ties.method = c("max", "average",
  "min"), dim. = dim(x), preserveShape = FALSE, ...)

Arguments

`x`	A `numeric` or `integer` NxK `matrix`.
`rows, cols`	A `vector` indicating subset of rows (and/or columns) to operate over. If `NULL`, no subsetting is done.
`ties.method`	A `character` string specifying how ties are treated. For details, see below.
`dim.`	An `integer` `vector` of length two specifying the dimension of `x`, also when not a `matrix`.
`...`	Not used.
`preserveShape`	A `logical` specifying whether the `matrix` returned should preserve the input shape of `x`, or not.

Details

The row ranks of x are collected as rows of the result matrix.

The column ranks of x are collected as rows if preserveShape = FALSE, otherwise as columns.

The implementation is optimized for both speed and memory. To avoid coercing to doubles (and hence memory allocation), there is a unique implementation for integer matrices. It is more memory efficient to do colRanks(x, preserveShape = TRUE) than t(colRanks(x, preserveShape = FALSE)).

Any names of x are ignored and absent in the result.

Value

An integer matrix is returned. The rowRanks() function always returns an NxK matrix, where N (K) is the number of rows (columns) whose ranks are calculated.

The colRanks() function returns an NxK matrix, if preserveShape = TRUE, otherwise a KxN matrix.

for double.

Missing and non- values

These are ranked as NA, as with na.last = "keep" in the rank() function.

Author(s)

Hector Corrada Bravo and Harris Jaffee. Peter Langfelder for adding 'ties.method' support. Henrik Bengtsson adapted the original native implementation of rowRanks() from Robert Gentleman's rowQ() in the Biobase package.