trigamma {MASS}R Documentation

Trigamma Function

Description

Calculates the trigamma function, which is the second derivative of the logarithm of the gamma function, for complex vector arguments.

Usage

trigamma(z)

Arguments

z Vector argument. May be real or complex but must have positive real part.

Details

Uses an asymptotic expansion where Re(z) > 5 and a recurrence formula to such a case where Re(z) <= 5. Accuracy is good.

Value

Vector of trigamma(z) values.

References

M. Abramowitz and I. A. Stegun (1965) Handbook of Mathematical Functions. Dover.

See Also

digamma


[Package Contents]