Percentiles

[pbreheny]

Feature request: I'm not sure how much work would be involved in implementing this, but I think it would be very useful to have a function to return percentiles for downloads, in order to be able to say things like "package X is in the top 10% of downloaded packages from CRAN".

[gaborcsardi]

Good idea. I don't think it is difficult to implement. You want to help with it? :)

A new SQL (plpgsql) procedure is needed here: https://github.com/metacran/cranlogs.app/blob/master/db/proc.sql

[pbreheny]

Hmm...well, I'm not sure I know enough SQL/JSON to be of much help. Algorithmically, it would seem to require:

1. Get names of all CRAN packages
2. Run cran_downloads on that list
3. Calculate quantiles

2 and 3 are straightforward. 1 is clearly possible, but I wouldn't know how to do it through the SQL/JSON interface. Or perhaps there's a more efficient approach than all this?