Re: [Fwd: Re: gnuplot numerical errors on Intel MacBook]

[Daniel J S. <dan...@ie...>]

Ethan Merritt wrote:
> On Thursday 28 September 2006 11:57 am, Daniel J Sebald wrote:
>=20
>>Hans-Bernhard Br=F6ker wrote:
>>
>>>Daniel J Sebald wrote:
>>>
>>> > So perhaps it has no meaning anymore for Apple's platform.
>>>
>>>That's not Appple's decision to make.
>>>
>>> > Why they would still have the variable in
>>> > the library if that were the case, I'm not sure.
>>>
>>>They must have it, and they must use it as defined in all
>>>applicable standards.
>>
>>I'm guessing the concept
>>is to move away from signgam, I believe, for which the
>>non-threadedness may have played a factor in their decision.
>=20
>=20
> Given that in order to be mathematically correct the sign=20
> information must be present *somewhere*, this leaves two options.
> (1) lgamma_r(double x, int *signp)
> (2) tgamma

That's why in the second version of the patch these two have precedence (=
tgamma higher than lgamma_r).  Using lgamma_r doesn't complicate matters.

But if there is some library out there that implements "gamma()" as the t=
rue gamma and inherently has sign information, that will work too.  One c=
an argue that would only be a tiny percentage of platforms, granted.

Dan