Symbolic Gamma Functions
• Psi(z)—Returns the derivative of the natural logarithm of the gamma function Γ(z). The digamma function is defined as follows:
• Psi(n, z)—Returns the nth derivative of Psi(z). The polygamma function is defined as follows:
Psi(z) relates to Psi(n, z) as follows:
Arguments
• z is a real or complex scalar, or a vector of real or complex scalars.
• n is a nonnegative integer.
Additional Information
• You can evaluate the single argument version of the Psi function both symbolically and numerically. If you evaluate it numerically, then z can also be a complex scalar or a vector of complex scalars.
• You can evaluate the two argument version of the Psi function only symbolically.