gdtrc

Complemented gamma distribution function.

SYNOPSIS:

double a, b, x, y, gdtrc();
y = gdtrc(a, b, x);

DESCRIPTION:

Returns the integral from x to infinity of the gamma probability density function:

               inf.
        b       -
       a       | |   b-1 -at
y = -----    |    t    e    dt
       -     | |
      | (b)   -
               x

The incomplete gamma integral is used, according to the relation:

y = igamc(b, ax).

ACCURACY:

See the igamc() Help topic.

ERROR MESSAGES:

   message      condition      value returned
   domain         x < 0            0.0