On Feb 11, 2014 6:57 PM, <ref...@uncg.edu> wrote: > > Dear All, > > I was developing an algorithm that depended on the calculation of the gamma function. I noticed that the algorithm was surprisingly slow. Upon investigation, I realized that the issue lies with the gamma function. To illustrate: > > sage: RR = RealField(1000) > sage: CC = ComplexField(1000) > sage: %timeit RR(-3.52).gamma() > 100 loops, best of 3: 3.58 ms per loop > sage: %timeit CC(-3.52).gamma() > 1000 loops, best of 3: 538 us per loop > > This surprised me. I figured it was because of the high precision, but the next example shows it isn't. > > sage: RR > Real Field with 53 bits of precision > sage: CC > Complex Field with 53 bits of precision > sage: %timeit RR(-3.52).gamma() > 10000 loops, best of 3: 136 us per loop > sage: %timeit CC(-3.52).gamma() > 10000 loops, best of 3: 77.9 us per loop > > After some investigation, the reason lies in the fact that version RR version gamma uses mpfr directly to compute gamma. On the other hand, the CC version of gamma uses pari to compute the gamma function. Is there a reason for this that I'm not seeing? >
What is "this"? If this="use pari instead of mpfr", then the reason is because mpfr=multiprecision floating *reals*... Does mpc have a library function to compute gamma? > I'm new to development, so I'm not sure if I should have posted this question here. Should I have submitted a ticket first? > > Thanks, > > Rick > > -- > You received this message because you are subscribed to the Google Groups "sage-devel" group. > To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. > To post to this group, send email to sage-devel@googlegroups.com. > Visit this group at http://groups.google.com/group/sage-devel. > For more options, visit https://groups.google.com/groups/opt_out. -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/groups/opt_out.
