Thank-you: that was exactly the problem. Merely replacing Math::Big::factorial with Math::BigFloat::bfac fixed it. The code's below for posterity's sake:

use strict;
use Math::BigFloat;

my $G = 11057;    #$ARGV[0];
my $C = $ARGV[0];
my $n = $ARGV[1];
my $k = $ARGV[2];

sub choose {

    my $ret_val    = Math::BigFloat->new();
    my $n        = Math::BigFloat->new($_[0]);
    my $r        = Math::BigFloat->new($_[1]);
    my $n_r        = Math::BigFloat->new($_[0] - $_[1]);

    $n->bfac();
    $r->bfac();
    $n_r->bfac();

    $ret_val = $n / ($n_r * $r);

    return $ret_val;

    }

my $p = Math::BigFloat->new('1');
my $denom = Math::BigFloat->new(choose($G, $n));

for (my $i = 0; $i < $k; $i++) {

    my $val1 = $G - $C;
    my $val2 = $n - $i;

    my $delta = Math::BigFloat->new();
    $delta = choose($C, $i) * choose($val1, $val2) / $denom;
    $p -= $delta;
    }

print "Probability estimate: $p\n";

[download]

In reply to Re: Re: Hypergeometric Probability Calculation by Itatsumaki
in thread Hypergeometric Probability Calculation by Itatsumaki

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.