Re: NFactorial[n_], fast for large (n).
- To: mathgroup@smc.vnet.net
- Subject: [mg12581] Re: [mg12506] NFactorial[n_], fast for large (n).
- From: "Jrgen Tischer" <jtischer@pitagoras.univalle.edu.co>
- Date: Mon, 25 May 1998 14:24:52 -0400
Ted, you're kidding. Try 12000.!, check once more your examples and you
will see: it isn't you who is making the fast implementations, its
wolfram.
Jrgen
-----Original Message-----
From: Ersek_Ted%PAX1A@mr.nawcad.navy.mil To: mathgroup@smc.vnet.net
<Ersek_Ted%PAX1A@mr.nawcad.navy.mil> Subject: [mg12581] [mg12506] NFactorial[n_],
fast for large (n).
> If (num) is a large integer N[ num! ] computes the exact value of
> (num!),
> and then converts it to a less precise value. This can take a
> relatively long time (see below).
>
> In[1]:=
> N[12000!];//Timing
>
> Out[1]=
> {10.16 Second,Null}
>
> But (n!) == Gamma[n+1]
> So I define a function NFactorial[n_Integer]
>
> In[2]:=
.......