[Maxima] Accuracy of numerical calculation of the Gamma and Beta function
adammaj1 at o2.pl
Sat Oct 11 02:20:37 CDT 2008
Thx for intresting results.
> Results for double float precision:
> maxerr = 1.88e-13 (formula r2)
> maxerr = 2.29e-13 (formula r3)
> Result for bigfloat precision:
> fpprec maxerr r2 maxerr r3
> 16 3.24b-14 3.58b-14
> 32 3.84b-30 3.99b-30
> 64 7.87b-62 9.48b-62
Can you also show time of computations ? ( How it grows with fpprec )
> There is no significant difference beetween the different algorithm. The
> algoritm using log_gamma seems to be sligthly less accurate. Perhaps something
> in the routines for log_gamma can be done better.
> In bigfloat precision we can achieve any desired accuracy. We have a systematic
> difference of 2 to 4 digits in accuracy.
Does it mean that Maxima can also be used not only as a CAS but also for
numerical calculations ?
Sometimes I (in my opinion) it's hard to change fpprec in Maxima, see
Is it possible to change it ? ( to do it with simple one command fpprec)
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