Maxima 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 ,
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.