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Re: testing besjn
- From: Steve Kargl <sgk at troutmask dot apl dot washington dot edu>
- To: Tobias Burnus <tobias dot burnus at physik dot fu-berlin dot de>
- Cc: fortran at gcc dot gnu dot org
- Date: Thu, 25 Feb 2010 21:14:59 -0800
- Subject: Re: testing besjn
- References: <20100226002333.GA15492@physik.fu-berlin.de>
On Fri, Feb 26, 2010 at 01:23:33AM +0100, Tobias Burnus wrote:
> Dear Steve,
>
> If I run
> real(4) :: r4 = 2.4048255576957729_8
> real(8) :: r8 = 2.4048255576957729_8
> real(10):: r10 = 2.4048255576957729_8
You might need additional decimal digits in the r10 value
to get the infinity.
> print *, besjn(3,r4)
> print *, besjn(3,r8)
> print *, besjn(3,r10)
> print *, besjn(3,2.4048255576957729_4)
> print *, besjn(3,2.4048255576957729_8)
> print *, besjn(3,2.4048255576957729_10)
> with GLIBC 2.11.1 (20100118) of openSUSE, I get the following result
> for -m64 (x86-64):
> 0.23056939
> -Infinity
> 0.19899961853217685017
This, however, suggest that the problem is in jnf, jn, and jnl.
> 0.19899988
> 0.19899990535769083
> 0.19899990535769083403
These are the expected values, which are generated by MPFR
(which I think you already know but others might not).
Thanks for running the test.
--
Steve