how do you find the median of 2 columns using R?

Question

I am trying to compute the median vector of a data set s with column A1 and B1 . The median vector is the median for each observation from both columns.

I tried to do this and it did not work.

median(s[c("A1","B1")])

Is there another way to do it?

Answer 1

The median of two observations is simply the mean. So rowMeans(s[,c("A1","B1")]) . Equivalently, apply(s[,c("A1","B1")],1,median)

Answer 2

Another solution:

library(plyr)
colwise(median)(s[c("A1", "B1")])

which has the advantage of returning a data frame.