Psi: Psi (digamma) functions

In gsl: Wrapper for the Gnu Scientific Library

Psi (digamma) functions

Description

Psi (digamma) functions as per the Gnu Scientific Library, reference manual section 7.27. These functions are declared in header file gsl_sf_psi.h

Usage

psi_int(n, give=FALSE, strict=TRUE)
psi(x, give=FALSE, strict=TRUE)
psi_1piy(y, give=FALSE, strict=TRUE)
psi_1_int(n, give=FALSE, strict=TRUE)
psi_1(x, give=FALSE, strict=TRUE)
psi_n(m, x, give=FALSE, strict=TRUE)

Arguments

m,n	input: integer values
x,y	input: real values
give	Boolean with TRUE meaning to return a list of three items: the value, an estimate of the error, and a status number
strict	Boolean, with default TRUE meaning to return NaN if status is an error

Author(s)

Robin K. S. Hankin

References

https://www.gnu.org/software/gsl/

Examples

x <- seq(from=1.2,to=1.25,by=0.005)
cbind(x,psi(x),psi_1(x))
#tabe 6.1, p267, bottom bit

psi_int(1:6)
psi(pi+(1:6))
psi_1piy(pi+(1:6))
psi_1_int(1:6)
psi_n(m=5,x=c(1.123,1.6523))

gsl documentation built on Feb. 16, 2023, 10:32 p.m.