gamma

Purpose

Returns the value of the gamma function.

Format

g = gamma(x)
Parameters:x (NxK matrix or N-dimensional array) – the values used to evaluate the gamma function.
Returns:g (NxK matrix or N-dimensional array) – the value of the gamma function evaluated at x.

Examples

g = gamma(2.5);

After the code above:

g = 1.329340

Remarks

For each element of x this function returns the integral

\[\int_{0}^{\infty}t^{(x−1)⁢}e^{−t}dt\]

All elements of x must be positive and less than or equal to 169. Values of x greater than 169 will cause an overflow.

The natural log of gamma() is often what is required and it can be computed without the overflow problems of gamma() using lnfact().

See also

Functions cdfchic(), cdfbeta(), cdffc(), cdfnc(), cdftc(), erf(), erfc(), lnfact()