plot numerical question



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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