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On 13/12/18 10:39 AM, Alan Braslau wrote:
On Thu, 13 Dec 2018 10:03:40 +1300 Henri Menke
wrote: Sorry, my mistake, the Bessel functions are not a GCC extension but POSIX standard functions. http://pubs.opengroup.org/onlinepubs/9699919799/functions/j0.html Since TeX Live is always built on a POSIX platform (MSYS2 on Windows), you can expect j0 etc. to be available in LuaTeX.
That is true for the Bessel functions, but not for some other "-lmath" functions (such as the erf), so they may depend on the system.
erf definitely does not depend on the system. That is part of the C Standard library. https://en.cppreference.com/w/c/numeric/math/erf But in general you are right. The zoo of special functions in the Standard library and POSIX is rather limited. Personally I prefer using the GNU Scientific library if I need special functions. https://www.gnu.org/software/gsl/doc/html/index.html Earlier this year I wrote a TUGboat article about using GSL with FFI in LuaTeX. https://tug.org/TUGboat/tb39-1/tb121menke-ffi.pdf I also plan on submitting an abstract about that topic for TUG2019 in Palo Alto.
Alan