Not at all. I am well aware of makegamma, and I have been
using it exactly as you are showing, with stirling (though
I didn't know you wrote it). The plot question I posted was
a simplified version of what I am actually doing, which is
trying to see the effects of the Stirling approximation in a
more complicated case.
Kostas
Barton Willis wrote:
> By the way:
>
> (%i64) makegamma(s!/(((s/4)!)^4 * 4^s));
> (%o64) gamma(s+1)/(gamma(s/4+1)^4*4^s)
>
> (%i65) stirling(%,2);
> (%o65)
> (sqrt(2)*(s+1)^(s+1/2)*%e^(1/(12*(s+1))-s-4*(-s/4+1/(12*(s/4+1))-1)-1))/(4*%pi^(3/2)*(s/4+1)^(4*(s/4+1/2))*4^s)
>
> (%i66) taylor(%,s,inf,2);
> (%o66) (4*sqrt(2))/(sqrt(%pi)*%pi*s^(3/2))+...
>
> (sorry for the shameless plug for (my) stirling package).
>
>
> Barton
>
> maxima-bounces at math.utexas.edu wrote on 03/11/2009 02:36:43 PM:
>
>
>> I have a function
>>
>> r4(s) := s!/(((s/4)!)^4 * 4^s)
>>
>> and I am trying to plot it over the range [200,300]:
>>
>> plot2d(r4(s), [s,200,300])
>>
>> plot2d returns silently, i.e. it produces nothing. I am
>> fairly sure the problem is that the computation involves
>> intermediate numbers that are too large, although the final
>> result is well within the rang of an ordinary float. E.g.
>> r4(300) is of the order of 10^-4.
>>
>> I thought I had seen a solution to this kind of problem with
>> plot somewhere on the list, but I can't find it. It seems
>> to me the answer would be worth adding to the documentation
>> for plotting.
>>
>> (This is Maxima 5.17.1 using SBCL, same with CMUCL)
>>
>> Kostas
>>
>>
>> _______________________________________________
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>