Re: [Help-gsl] Double vs Long Double

[Brian Gough]

At Sat, 29 Sep 2007 00:50:38 +0000 (GMT),
address@hidden wrote:
> 
> I just got the  GSL book today and immediately
> tried the sample program on page 9.
> 
> I did not get the exact same answer shown in the book:
>       JO(5) = -1.775967713143382920e-01
> I got J)(5) = -1.775967713143382642e-01
>                                 ^^^
> I'm running 64-bit AMD OpenBSD 4.1 on AM2 Athlon 64.

Thanks for your email.  The results vary in the final bit, 1ulp =
2e-16.  There are many factors which can affect the result at this
level (compiler options, order of rounding, etc) -- I've added a note
to the manual that this is normal.

-- 
Brian Gough