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/GNU Fortran 7

9.41 BESSEL_J1 — Bessel function of the first kind of order 1

Description:

BESSEL_J1(X) computes the Bessel function of the first kind of order 1 of X. This function is available under the name BESJ1 as a GNU extension.

Standard:

Fortran 2008

Class:

Elemental function

Syntax:

RESULT = BESSEL_J1(X)

Arguments:
X The type shall be REAL.
Return value:

The return value is of type REAL and lies in the range - 0.5818... \leq Bessel (0,x) \leq 0.5818 . It has the same kind as X.

Example:
program test_besj1
  real(8) :: x = 1.0_8
  x = bessel_j1(x)
end program test_besj1
Specific names:
Name Argument Return type Standard
DBESJ1(X) REAL(8) X REAL(8) GNU extension

© Free Software Foundation
Licensed under the GNU Free Documentation License, Version 1.3.
https://gcc.gnu.org/onlinedocs/gcc-7.1.0/gfortran/BESSEL_005fJ1.html