Psi function

Psi function, also known as digamma function, is defined as

This function is calculated by Psi subroutine.

This article is intended for personal use only.

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C# source.

C++ source.

C++ source. MPFR/GMP is used.

GMP source is available from gmplib.org. MPFR source is available from www.mpfr.org.

FreePascal version.

Delphi version.

VB.NET version.

VBA version.

Python version (CPython and IronPython are supported).