besselj, a Python code which evaluates Bessel J functions of noninteger order.

At the moment, this code simply consists of a test case for the scipy.special.jv(nu,x) function. Later, the source code for some other implementations of the Bessel J function may be added.


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:

polpak, a Python code which evaluates certain mathematical functions, especially some recursive polynomial families.


  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:

Last revised on 18 January 2020.