pdtrc

Complemented poisson distribution.

SYNOPSIS:

int k;
double m, y, pdtrc();
y = pdtrc(k, m);

DESCRIPTION:

Returns the sum of the terms k+1 to infinity of the Poisson distribution:

inf.       j
   --   -m m
   >   e    --
   --       j!
j=k+1

The terms are not summed directly; instead the incomplete gamma integral is employed, according to the formula:

y = pdtrc(k, m) = igam(k+1, m).

The arguments must both be positive.

ACCURACY:
See the igam Help topic.