Lahey/GNU Fortran

Next: , Previous: BESSEL_J0, Up: Intrinsic Procedures

### 8.27 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, 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 . 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