| Pré. | Proc. |
gdtr
Gamma distribution function.SYNOPSIS:
double a, b, x, y, gdtr();
y = gdtr(a, b, x);
DESCRIPTION:
Returns the integral from zero to x of the gamma probability density function:
x
b -
a | | b-1 -at
y = ----- | t e dt
- | |
| (b) -
0
The incomplete gamma integral is used, according to the relation:
y = igam(b, ax).
ACCURACY:
See the igam() Help topic.
ERROR MESSAGES:
message condition value returned
domain x < 0 0.0