psexpand SciMax Toolbox psi

SciMax Toolbox >> psi

psi

Maxima Function

Calling Sequence

psi [n](x)

Description

The derivative of log (gamma (x)) of order n+1. Thus, psi[0](x) is the first derivative, psi[1](x) is the second derivative, etc.

Maxima does not know how, in general, to compute a numerical value of psi, but it can compute some exact values for rational args. Several variables control what range of rational args psi will return an exact value, if possible. See , maxpsinegint, maxpsifracnum, and maxpsifracnum. That is, x must lie between maxpsinegint and maxpsiposint. If the absolute value of the fractional part of x is rational and has a numerator less than maxpsifracnum and has a denominator less than maxpsifracdenom, psi will return an exact value.

The function bfpsi in the bffac package can compute numerical values.

psexpand SciMax Toolbox psi