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C Library Functions  - besk (3)

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NAME

besk(3f) - [M_bessel] compute the K Bessel function for a given argument and order

CONTENTS

Synopsis
Description
Options
Subroutines And Function Subprograms Required
Example

SYNOPSIS

subroutine besk(x,n,bk,ier)

DESCRIPTION

    METHOD

Computes zero order and first order Bessel functions using series approximations and then computes Nth order function using recurrence relation. Recurrence relation and polynomial approximation technique as described by A.J.M.Hitchcock,"Polynomial Approximations to Bessel Functions of Order Zero and One and to Related Functions", M.T.A.C., V.11,1957,PP.86-88, and G.N. Watson, "A Treatise on the Theory of Bessel Functions", Cambridge University Press, 1958, P. 62

OPTIONS

    DESCRIPTION OF PARAMETERS

X	The argument of the K Bessel function desired
N	The order of the K Bessel function desired
BK	The resultant K Bessel function
IER	resultant error code where

                IER=0  No error
                IER=1  N is negative
                IER=2  X is zero or negative
                IER=3  X .GT. 170, Machine range exceeded
                IER=4  BK .GT. 10**70

    REMARKS

N must be greater than or equal to zero

SUBROUTINES AND FUNCTION SUBPROGRAMS REQUIRED

none

EXAMPLE

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Nemo Release 3.1

besk (3)

June 29, 2025

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