PolyGamma

Usage

• PolyGamma[z] gives the digamma function .
• PolyGamma[n, z] gives the derivative of the digamma function .

Notes

• PolyGamma[z] is the logarithmic derivative of the gamma function, given by

• PolyGamma[n, z] is given by

• The digamma function is

;

is the

logarithmic derivative of the gamma function.

• PolyGamma[z] and PolyGamma[n, z] are meromorphic functions of z with no branch cut discontinuities.

• FullSimplify and FunctionExpand include transformation rules for PolyGamma.

• Implementation notes: see Section A.9.4.

• New in Version 1.