Another chi-squared routine

[Greg Louis]

On 20030119 (Sun) at 1940:55 +0100, Matthias Andree wrote:
> Greg Louis <glouis at dynamicro.on.ca> writes:
> 
> > functions, including chi-squared; but the chi-squared routine returns
> > probability density rather than cumulative values.  That's ok, though,
> > because a fast integration routine is provided as well.
> 
> What now? cumulation or integration? They are sorta different.

Integrating the density function from chi-square 0 (I used 0.0001,
chi-square should be >0) to the value of interest yields the cumulative
probability.

> > Since the gsl compiles easily as a shared library, we could switch and
> > not have to carry our own truncated dcdflib in the distribution in
> > order to keep the executable size down.  This may not be deemed
> > desirable, though, since doing so would add another package dependency
> > to bogofilter, and not everyone needs numerical analysis stuff in
> > /usr/lib, handy as it might be for some of us ;)
> 
> It might be desirable for licensing issues though. If there's something
> clear about FSF, it's their licensing.
> 
Good point.  The dcdflib is restricted in that "General permission to
copy and distribute the algorithm[s] without fee is granted provided
that the copies are not made or distributed for direct commercial
advantage, the ACM copyright notice and the title of the publication
and its date appear, and notice is given that copying is by permission
of the Association for Computing Machinery.  To copy otherwise, or to
republish, requires a fee and/or specific permission."  Some of the
code is in the public domain; algorithms and code that appeared in an
ACM publication are not.

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Subject: Re: Another chi-squared routine
     To: bogofilter-dev <bogofilter-dev at aotto.com>
   From: Greg Louis <glouis at dynamicro.on.ca>
   Date: Mon, 20 Jan 2003 07:01:32 -0500