Re: [Gnuplot-info] Factorial issue

[Tim W. <ti...@ie...>]

On Mon, Feb 08, 2010 at 07:15:21AM -0800, Philipp K. Janert wrote:
> On Sunday 07 February 2010 11:07:07 am Tim Wojtulewicz wrote:
> > I'm working with a fairly complicated function, one part of which is the
> > division of two factorials.  I'm having an issue with though, because
> > gnuplot keeps returning NaN for what should be a simple division.  It will
> > return NaN for something as simple as 100!/99!, which should just be 100. 
> > Is there a reason for this, or an easy way to fix it?  Thanks.
> 
> The intermediate results overflow, despite the fact that
> the final result is of meaningful size.
> 
> Either work out the cancellations analytically, or work with
> logarithms of all quantities (Stirlings approximation!), and
> exponentiate at the end (if needed).
> 

So is this a version issue then?  The reply from Thomas seems like his
is working correctly.  I'm working with version 4.2.5 on OS X 10.6.
It's odd that his would work, and yet mine won't.

Tim