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

rowOrderStats {matrixStats}

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

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

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

Arguments

`x`	A `numeric` NxK `matrix`.
`rows, 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`.
`...`	Not used.

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)

The native implementation of rowOrderStats() was adopted by Henrik Bengtsson from Robert Gentleman's rowQ() in the Biobase package.