Re: [Boost-users] statistics: exact median, first and third quartile

Subject: Re: [Boost-users] statistics: exact median, first and third quartile
From: gast128 (gast128_at_[hidden])
Date: 2013-03-01 11:31:08

> > Thx, but are you sure? Median is defined as the middle element in odd
> > distributions but is the average of the 2 middle elements in even
> > distributions.
> 
> So? For a collection c of size 2n, you would use:
> 
> nth_element( begin(c), begin(c) + n - 1, end(c) );
> nth_element( begin(c), begin(c) + n, end(c) );
> auto median = (c[n - 1] + c[n]) / 2;

Yes however nth_element has some overhead so doing it twice is not advisable.
Ofc u can fix that (by either partial sort etc.), but the best thing was:

auto med = boost::median(itBegin, itEnd); (//or std::)