Re: Problem and solution: Patch for new "stats" command

[ZoltánVörös <zv...@gm...>]

Tait <gnuplot-devel <at> t41t.com> writes:

> 
> Mean as used here seems to be the arithmetic mean. What about the geometric
> mean? (Or harmonic mean, or any of the other types of averages?)

Harmonic mean is easily done with the present stats command as 
stats 'foo' u 1:(1.0/$2) noout var
harmonic = records / sum_y

> I have always addressed these sorts of issues by using a tool that's
> designed for manipulating arbitrary data sets (Perl in my case, but there
> are others). This has the advantage of providing infinite flexibility,

That is sort of a platform-dependent solution for a problem that comes up too
often, but Philipp has already discussed this issue at length, I believe.

> I wonder, rather than providing a restricted set of pre-defined functions,
> is there a way to allow the user to provide a formula or expression that
> will be applied across multiple rows? Then the user could calculate the
> mean (whatever that means to their application) or standard deviation or
> some other arbitrary metric on their own.

stats 'foo' u ($2*$3+cos($4)) should work as it is, if that is what you meant. A
fairly large set of quantities can be calculated using the variables that are
produced by stats, if the proper function is applied to the columns beforehand. 
Best,
Zoltán