Returns the gamma function of x.

The gamma function is normally defined for negative values of x as well, but Netica cannot compute these.

Don’t confuse this function with the gamma probability distribution.

Even fairly small values of x (around 170) can cause gamma to overflow.  For that reason calculations with the gamma function are often done using the logarithm of the results, for which you can use loggamma.

For integer values of x, the gamma function is related to the factorial function by: factorial (n) = gamma (n + 1)