digamma

fnreal digamma(real x)

Digamma function, Ψ(x)

Ψ(x), is the logarithmic derivative of the gamma function, Γ(x).

Ψ(x) = d/, dx ln|Γ(x)| (the derivative of logGamma(x))

Parameters

xthe domain value

Returns

It returns Ψ(x).
x, digamma(x) integer < 0, NaN ±0.0, +∞, +∞ -∞, NaN NaN, NaN

See Also

logmdigamma, logmdigammaInverse.