Re: tolerance in binopdf.m

[Marco Atzeri]

On 21/09/2011 7.23, Rik wrote:
> On 09/20/2011 08:50 PM, Ben Abbott wrote:
> > On Sep 20, 2011, at 9:03 PM, Ben Abbott wrote:

> > Looking at these individually ...
> >
> > printf ("%.17f\n", log (0.5))
> > -0.69314718055994529
> >   printf ("%.17f\n", gammaln (3))
> > 0.69314718055994540
> >
> > Does anyone have any insight regarding this?
> >
> > What does Linux give for these two?
> Ubuntu 10.04 with libc 2.11.1 gives 0 everywhere you would expect it to.
> In particular,
>
>   printf ("%.17f\n", gammaln (3))
>
> 0.69314718055994529
>
> As Jordi pointed out, for my system HAVE_LGAMMA=1 is defined so I should be
> grabbing it from libc.
>
> -
same on cygwin

config.status:D["HAVE_LGAMMA"]=" 1"
config.status:D["HAVE_LGAMMAF"]=" 1"
config.status:D["HAVE_LGAMMA_R"]=" 1"
config.status:D["HAVE_LGAMMAF_R"]=" 1"

octave:1> printf ("%.17f\n", log (0.5))
-0.69314718055994529
octave:2> printf ("%.17f\n", gammaln (3))
0.69314718055994529

Marco