[datatable-help] Fast first row of each group

[Matthew Dowle]

Hi Steve,

Have posted a follow up to your answer here :

http://stats.stackexchange.com/questions/7884/fast-ways-in-r-to-get-the-first-row-of-a-data-frame-grouped-by-an-identifier/7985#7985

Thought it might be of interest on list as it's such a large difference.

I realise this probably isn't clear in the documentation or FAQs, so
have added todo to make that clearer.

Btw, could somebody vote me up please - I have 1 point and can't make
comments!

Matthew