Sfun.GammaIncomplete Method |
Namespace: Imsl.Math
The lower limit of integration of the incomplete gamma function,
, is defined to be
Although is well defined for
, this algorithm does not calculate
for negative x. For large a
and sufficiently large x,
may overflow.
is bounded by
, and users may find this bound a useful guide in
determining legal values for a.
Note that the upper limit of integration of the incomplete gamma,
, is defined to be
Therefore, by definition, the two incomplete gamma function forms satisfy the relationship