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Unfortunately, it looks like the Cephes library of mathematical functions linked from this article is released with a poorly specified license, and contains cod

Unfortunately, it looks like the Cephes library of mathematical functions linked from this article is released with a poorly specified license, and contains code that is copyrighted by multiple organizations: http://www.netlib.org/cephes/readme http://www.netlib.org/cephes/readme

hga 12y ago
A bit of Debian discussion and interaction with the author on this: https://lists.debian.org/debian-legal/2004/12/msg00295.html https://lists.debian.org/debian-legal/2004/12/msg00295.html
andy_wrote 12y ago
The GNU Scientific Library (GSL) covers these functions and is GPLed: http://www.gnu.org/software/gsl/ http://www.gnu.org/software/gsl/ GSL's design doc (https://www.gnu.org/software/gsl/design/gsl-design.html https://www.gnu.org/software/gsl/design/gsl-design.html) explicitly names many libraries, including CEPHES, that its creators consider useful but with drawbacks, such as non-free licensing, that motivated GSL's creation. I'm not especially familiar with GSL except for a few functions I've used on occasion, and not with CEPHES at all, so I can't speak to other pros or cons.
- nullc 12y ago
  GSL is pretty fantastic though it's not insanely high performance and doesn't accommodate extended precision types.
gone35 12y ago
[Edit: I overlooked the fact that, being free under GPL, the GSL implementations do not suit the author's intent. (See /jwmerrill's comment below). Leaving the comment anyway just for reference, but my original point is moot.] This. The author should have at least mentioned the ubiquituous and reasonably well-maintained GNU Scientific Library (GSL) [1], which already implements all the functions listed in the article [2,3,4,5], among many, many other things [6]. [1] http://www.gnu.org/software/gsl/ http://www.gnu.org/software/gsl/ [2] http://www.gnu.org/software/gsl/manual/html_node/Incomplete-Gamma-Functions.html#Incomplete-Gamma-Functions http://www.gnu.org/software/gsl/manual/html_node/Incomplete-... [3] http://www.gnu.org/software/gsl/manual/html_node/Incomplete-Beta-Function.html#Incomplete-Beta-Function http://www.gnu.org/software/gsl/manual/html_node/Incomplete-... [4] http://www.gnu.org/software/gsl/manual/html_node/The-Gaussian-Distribution.html#The-Gaussian-Distribution http://www.gnu.org/software/gsl/manual/html_node/The-Gaussia... [5] http://www.gnu.org/software/gsl/manual/html_node/Bessel-Functions.html#Bessel-Functions http://www.gnu.org/software/gsl/manual/html_node/Bessel-Func... [6] http://www.gnu.org/software/gsl/manual/html_node/ http://www.gnu.org/software/gsl/manual/html_node/
- jwmerrill 12y ago
  The gsl is a great resource, but I don't think it suits the author's purpose. He is talking about adding new functions to the C standard library, for anyone to use in commercial or non-commercial software. It isn't practical to stick GPL code into C standard libraries that are meant to be used broadly in commercial as well as free software.
  - gone35 12y ago
    You are absolutely right. Now I see why the author didn't mention it. That was a knee-jerk reaction on my part.
GFK_of_xmaspast 12y ago
How is the cephes license non-free?
mindcrime 12y ago
Presumably if the "C" committee decided to do this, implementers would be free to implement this by various means, whether it be a clean-room version, or by adopting existing code. In the latter case, they could contact the author(s) of Cephes and try to arrange more suitable licensing if needed. Admittedly it adds a little extra friction to the process, but this doesn't seem like an insurmountable problem off hand.

hga 12y ago

A bit of Debian discussion and interaction with the author on this: https://lists.debian.org/debian-legal/2004/12/msg00295.html https://lists.debian.org/debian-legal/2004/12/msg00295.html

andy_wrote 12y ago

The GNU Scientific Library (GSL) covers these functions and is GPLed: http://www.gnu.org/software/gsl/ http://www.gnu.org/software/gsl/ GSL's design doc (https://www.gnu.org/software/gsl/design/gsl-design.html https://www.gnu.org/software/gsl/design/gsl-design.html) explicitly names many libraries, including CEPHES, that its creators consider useful but with drawbacks, such as non-free licensing, that motivated GSL's creation. I'm not especially familiar with GSL except for a few functions I've used on occasion, and not with CEPHES at all, so I can't speak to other pros or cons.

nullc 12y ago
GSL is pretty fantastic though it's not insanely high performance and doesn't accommodate extended precision types.

gone35 12y ago

[Edit: I overlooked the fact that, being free under GPL, the GSL implementations do not suit the author's intent. (See /jwmerrill's comment below). Leaving the comment anyway just for reference, but my original point is moot.] This. The author should have at least mentioned the ubiquituous and reasonably well-maintained GNU Scientific Library (GSL) [1], which already implements all the functions listed in the article [2,3,4,5], among many, many other things [6]. [1] http://www.gnu.org/software/gsl/ http://www.gnu.org/software/gsl/ [2] http://www.gnu.org/software/gsl/manual/html_node/Incomplete-Gamma-Functions.html#Incomplete-Gamma-Functions http://www.gnu.org/software/gsl/manual/html_node/Incomplete-... [3] http://www.gnu.org/software/gsl/manual/html_node/Incomplete-Beta-Function.html#Incomplete-Beta-Function http://www.gnu.org/software/gsl/manual/html_node/Incomplete-... [4] http://www.gnu.org/software/gsl/manual/html_node/The-Gaussian-Distribution.html#The-Gaussian-Distribution http://www.gnu.org/software/gsl/manual/html_node/The-Gaussia... [5] http://www.gnu.org/software/gsl/manual/html_node/Bessel-Functions.html#Bessel-Functions http://www.gnu.org/software/gsl/manual/html_node/Bessel-Func... [6] http://www.gnu.org/software/gsl/manual/html_node/ http://www.gnu.org/software/gsl/manual/html_node/

jwmerrill 12y ago
The gsl is a great resource, but I don't think it suits the author's purpose. He is talking about adding new functions to the C standard library, for anyone to use in commercial or non-commercial software. It isn't practical to stick GPL code into C standard libraries that are meant to be used broadly in commercial as well as free software.
- gone35 12y ago
  You are absolutely right. Now I see why the author didn't mention it. That was a knee-jerk reaction on my part.

GFK_of_xmaspast 12y ago

How is the cephes license non-free?

mindcrime 12y ago

Presumably if the "C" committee decided to do this, implementers would be free to implement this by various means, whether it be a clean-room version, or by adopting existing code. In the latter case, they could contact the author(s) of Cephes and try to arrange more suitable licensing if needed. Admittedly it adds a little extra friction to the process, but this doesn't seem like an insurmountable problem off hand.