[R] any other fast method for median calculation

[Zheng, Xin (NIH) [C]]

Hi there,

I got a data frame with more than 200k columns. How could I get median of each column fast? mapply is the fastest function I know for that, it's not yet satisfied though. 

It seems function "median" in R calculates median by "sort" and "mean". I am wondering if there is another function with better algorithm.

Any hint?

Thanks,

Xin Zheng