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9.40 BESSEL_J0 — Bessel function of the first kind of order 0 ¶

Description:

BESSEL_J0(X) computes the Bessel function of the first kind of order 0 of X. This function is available under the name BESJ0 as a GNU extension.

Standard:

Fortran 2008 and later

Class:

Elemental function

Syntax:

RESULT = BESSEL_J0(X)

Arguments:

X	The type shall be REAL.

Return value:

The return value is of type REAL and lies in the range - 0.4027... \leq Bessel (0,x) \leq 1. It has the same kind as X.

Example:

program test_besj0
  real(8) :: x = 0.0_8
  x = bessel_j0(x)
end program test_besj0

Specific names:

Name	Argument	Return type	Standard
DBESJ0(X)	REAL(8) X	REAL(8)	GNU extension