dlgamma

derivative of gammaln function, psi function

Syntax

y = dlgamma(x)

Arguments

x: real vector
y: real vector with same size.

Description

dlgamma(x) evaluates, at all the elements of x the logarithmic derivative of the gamma function which corresponds also to the derivative of the gammaln function :

d(ln(Γ(x))/dx = dΓ(x)/dx . 1/Γ(x)

x must be real. Also known as the psi function.

Examples

dlgamma(0.5)

History

Version	Description
5.4.0	Overloading allowed for list, mlist, tlist and hypermatrix types.