# Fortran Wiki bessel_jn

## Description

bessel_jn(n, x) computes the Bessel function of the first kind of order n of x. If n and x are arrays, their ranks and shapes shall conform.

bessel_jn(n1, n2, x) returns an array with the Bessel functions of the first kind of the orders n1 to n2.

## Standard

Fortran 2008 and later

## Class

Elemental function, except for the transformational variant bessel_jn(n1, n2, x).

## Syntax

result = bessel_jn(n, x)
result = bessel_jn(n1, n2, x)

## Arguments

• n - Shall be a scalar or an array of type integer.
• n1 - Shall be a non-negative scalar of type integer.
• n2 - Shall be a non-negative scalar of type integer.
• x - Shall be a scalar or an array of type real. For bessel_jn(n1, n2, x) it shall be scalar.

## Return value

The return value is a scalar of type real. It has the same kind as x.

## Example

program test_besjn
real(8) :: x = 1.0_8
x = bessel_jn(5,x)
end program test_besjn