7.19 BESJ1 — Bessel function of the first kind of order 1

Description:

BESJ1(X) computes the Bessel function of the first kind of order 1 of X.

Option:

gnu

Class:

elemental function

Syntax:

X = BESJ1(X)

Arguments:

X	The type shall be REAL(*), and it shall be scalar.

Return value:

The return value is of type REAL(*) and it lies in the range - 0.5818... \leq Bessel (0,x) \leq 0.5818 .

Example:

          program test_besj1
            real(8) :: x = 1.0_8
            x = besj1(x)
          end program test_besj1
     

Specific names:

Name	Argument	Return type	Option
DBESJ1(X)	REAL(8) X	REAL(8)	gnu