BER0

This function evaluates the Kelvin function of the first kind, ber, of order zero.

Function Return Value

BER0 — Function value. (Output)

Required Arguments

X — Argument for which the function value is desired. (Input)
ABS(X) must be less than 119.

FORTRAN 90 Interface

Generic: BER0 (X)

Specific: The specific interface names are S_BER0 and D_BER0.

FORTRAN 77 Interface

Single: BER0 (X)

Double: The double precision name is DBER0.

Description

The Kelvin function ber0(x) is defined to be ℜJ0(xe3πi∕4). The Bessel function J0(x) is defined in BSJ0. Function BER0 is based on the work of Burgoyne (1963).

Example

In this example, ber0(0.4) is computed and printed.

 

USE BER0_INT

USE UMACH_INT

 

IMPLICIT NONE

! Declare variables

INTEGER NOUT

REAL VALUE, X

! Compute

X = 0.4

VALUE = BER0(X)

! Print the results

CALL UMACH (2, NOUT)

WRITE (NOUT,99999) X, VALUE

99999 FORMAT (' BER0(', F6.3, ') = ', F6.3)

END

Output

 

BER0( 0.400) = 1.000