rowMedians: Calculates the median for each row in a matrix

In Bioconductor/Biobase: Biobase: Base functions for Bioconductor

Calculates the median for each row in a matrix

Description

Calculates the median for each row in a matrix.

Usage

rowMedians(x, na.rm=FALSE, ...)

Arguments

x	A numeric NxK matrix.
na.rm	If TRUE, NAs are excluded first, otherwise not.
...	Not use.

Details

The implementation of rowMedians() is optimized for both speed and memory. To avoid coercing to doubles (and hence memory allocation), there is a special implementation for integer matrices. That is, if x is an integer matrix, then rowMedians(as.double(x)) would require three times the memory of rowMedians(x), but all this is avoided.

Value

Returns a numeric vector of length N.

Missing values

Missing values are excluded before calculating the medians.

Author(s)

Henrik Bengtsson

See Also

See rowMeans() in colSums().

Examples

set.seed(1)
x <- rnorm(n=234*543)
x[sample(1:length(x), size=0.1*length(x))] <- NA
dim(x) <- c(234,543)
y1 <- rowMedians(x, na.rm=TRUE)
y2 <- apply(x, MARGIN=1, FUN=median, na.rm=TRUE)
stopifnot(all.equal(y1, y2))

x <- cbind(x1=3, x2=c(4:1, 2:5))
stopifnot(all.equal(rowMeans(x), rowMedians(x)))

Bioconductor/Biobase documentation built on Nov. 2, 2024, 6:31 a.m.