gammaVer {DPQ} | R Documentation |

## Gamma Function Versions

### Description

Provide different variants or versions of computing the Gamma
(`\Gamma`

) function.

### Usage

```
gammaVer(x, version, traceLev = 0)
```

### Arguments

`x` |
numeric vector of absissa value for the Gamma function. |

`version` |
integer in {1,2,..,5} specifying which variant is desired. |

`traceLev` |
non-negative integer indicating the amount of diagnostic “tracing” output to the console during computation. |

### Details

All of these are good algorithms to compute `\Gamma(x)`

(for real
`x`

), and indeed correspond to the versions **R**'s implementation of
`gamma(x)`

over time. More specifically, the current version
numbers correspond to

.

.

.

Used in

**R**from ... up to versions 4.2.zPossibly to be used in

**R**4.3.z and newer.

### Value

numeric vector as `x`

### Author(s)

Martin Maechler

### References

.... TODO ....

### See Also

`gamma()`

, **R**'s own Gamma function.

### Examples

```
xx <- seq(-4, 10, by=1/2)
gx <- sapply(1:5, gammaVer, x=xx)
gamx <- gamma(xx)
cbind(xx, gx, gamma=gamx)
apply(gx, 2, all.equal, target=gamx, tol = 0) # typically: {T,T,T,T, 1.357e-16}
stopifnot( apply(gx, 2, all.equal, target = gamx, tol = 1e-14))
# even 2e-16 (Lnx, 64b, R 4.2.1)
```

[Package

*DPQ*version 0.5-8 Index]