# FN The Fullerton Function Library.

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

The original version of the library provided routines for single precision complex, single precision real, and double precision real arguments and used the prefixes "C" and "D" to indicate the complex and double precision versions.

This scheme has been modified for consistency, and also to avoid conflict with the names of functions commonly provided by various compilers. The prefixes "C4_", "R4_" and "R8_" are used to indicate functions for single precision complex, single precision real, and double precision real arguments. For example, the sine function can be calculated by the functions C4_SIN, R4_SIN or R8_SIN.

The original, true, correct version of FN is available through NETLIB: http://www.netlib.org/fn/index.html.

### Languages:

FN is available in a C version and a C++ version and a FORTRAN77 version and a FORTRAN90 version and a MATLAB version and a Python version.

### Related Data and Programs:

C4LIB, a MATLAB library which implements certain elementary functions for single precision complex variables;

C8LIB, a MATLAB library which implements certain elementary functions for double precision complex variables;

CLAUSEN, a MATLAB library which evaluates a Chebyshev approximant to the Clausen function Cl2(x).

MACHAR, a MATLAB library which computes the appropriate values of machine constants for a given machine.

LEGENDRE_POLYNOMIAL, a MATLAB library which evaluates the Legendre polynomial and associated functions.

MACHINE, a MATLAB library which stores the appropriate values of machine constants for a given machine.

R4LIB, a MATLAB library which contains many utility routines, using "R4" or "single precision real" arithmetic.

R8LIB, a MATLAB library which contains many utility routines, using "R8" or "double precision real" arithmetic.

TEST_VALUES, a MATLAB library which supplies test values of various mathematical functions.

### Reference:

1. Wayne Fullerton,
Portable Special Function Routines,
in Portability of Numerical Software,
edited by Wayne Cowell,
Lecture Notes in Computer Science, Volume 57, pages 452-483,
Springer 1977,
ISBN: 978-3-540-08446-4,
LC: QA297.W65.

### Examples and Tests:

You can go up one level to the MATLAB source codes.

Last revised on 24 April 2016.