I needed to count median as well as 25th and 75th percentile (though I can work without them) for a large dataset. For this I decided to use the Statistics::Descriptive.
I have dataset with ~30million numbers, but decided to use first 5m to limit the memory use (if someone has less memory using module, let me know) and I know that the variation between numbers is not that large so it should give me large enough set to work from. However I encountered a small problem. It doesn't return value for 25th percentile or 1st quartile. Has anyone encountered this before, should I go report this as bug?
I'm using Statistics::Descriptive 3.0100 (just hot off CPAN) and perl v5.10.0 (kubuntu 9.10).