Online Algebra Calculator
Many of users do not use powerful Maxima computer algebra system for systematic work, but for ad hoc algebraic calculations – equations, functions, matrixes, etc. only. To do this job, it is not useful to download the whole application from a web site.
Function: psi [<n>](<x>) 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 maxpsiposint, maxpsinegint, maxpsifracnum, and maxpsifracdenom. 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.
There are also some inexact matches for psi. Try ?? psi to see them.
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