(12-04-2014 06:14 AM)Bit Wrote: While it's a noticeable improvement, it's probably far from optimal since I'm not an expert on numerical algorithms, so I'd be interested in better versions.

Bit: When I was helping Torsten Manz improve his HP-15C simulator, I did a lot of research on good numerical algorithms, and one of the better examples of good coding and well selected numerical algorithms was the "Python" math library. The guys who wrote the Python math library used some really good algorithms. I also found that the Wolfram Alpha web site is a nice reference to check the accuracy of your algorithms. I don't know that your particular functions "Inverse Gamma" & "Inverse Factorial" are included in the Python math library, but if they are, they will probably be fast, accurate and interesting to look at as examples. Hope this helps, Barry