rowMedians {Biobase} | R Documentation |
Calculates the median for each row in a matrix.
rowMedians(imat, na.rm=FALSE)
imat |
|
na.rm |
If |
... |
Not use. |
Returns a double
vector
of length equal to number of rows in x
.
Missing values are excluded before calculating the medians.
This implementation is optimized for speed and memory to calculate.
As the example shows, this implementation is roughly 3-10 times faster
than using apply(x, MARGIN=1, FUN=medians)
.
As the example might show, the rowQ()
does not (have to)
handle missing values, and is therefore in some cases faster.
Henrik Bengtsson
See rowMeans()
in colSums
().
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)))