rowRanks: 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

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.

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.

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)).