The (complete) gamma function extends the factorial to real and complex numbers. The digamma and polygamma functions are defined by derivatives of the logarithm of the gamma function. The incomplete gamma function is a generalization of the complete gamma. Wolfram|Alpha can compute properties for all these gamma-type functions and can also be used as a calculator for them and other gamma-related functions.
Compute values for complete gamma, digamma, polygamma and incomplete gamma functions.