lowergamma: upper incomplete gamma function

This is the tgamma_lower from the boost library

Usage

lowergamma(a, z)

Arguments

a

The numeric 'a' parameter in the upper incomplete gamma

z

The numeric 'z' parameter in the upper incomplete gamma

Value

lowergamma results

Details

The lowergamma function is given by:

$$lowergamma(a, z) = \int_{0}^{z}t^{a-1}\cdot e^{-t} dt$$

Author

Matthew L. Fidler

Examples

lowergamma(1, 3)
#> [1] 0.9502129

lowergamma(1:3, 3)
#> [1] 0.9502129 0.8008517 1.1536198

lowergamma(1, 1:3)
#> [1] 0.6321206 0.8646647 0.9502129