Bessel J functions of noninteger order

BESSELJ is a MATLAB library which evaluates Bessel J functions of noninteger order.


The computer code and data files made available on this web page are distributed under the GNU LGPL license.


BESSELJ is available in a C version and a C++ version and a FORTRAN90 version and a MATLAB version and a Python version.

Related Data and Programs:

FN, a MATLAB library which approximates elementary and special functions using Chebyshev polynomials; functions include Airy, Bessel I, J, K and Y, beta, confluent hypergeometric, error, gamma, log gamma, Pochhammer, Spence; integrals include hyperbolic cosine, cosine, Dawson, exponential, logarithmic, hyperbolic sine, sine; by Wayne Fullerton.


  1. Donald Amos, SL Daniel, MK Weston,
    CDC 6600 subroutines IBESS and JBESS for Bessel functions I(NU,X) and J(NU,X),
    ACM Transactions on Mathematical Software,
    Volume 3, Number 1, March 1977, pages 76-92.
  2. William Cody,
    Algorithm 715: SPECFUN - A Portable FORTRAN Package of Special Function Routines and Test Drivers,
    ACM Transactions on Mathematical Software,
    Volume 19, Number 1, March 1993, pages 22-32.

Source Code:

Examples and Tests:

You can go up one level to the MATLAB codes.

Last revised on 13 January 2016.