view scripts/specfun/beta.m @ 2312:204cc7db6f4a

[project @ 1996-07-11 21:20:36 by jwe]
author jwe
date Thu, 11 Jul 1996 21:20:36 +0000
parents 2b5788792cad
children 5ca126254d15
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### Copyright (C) 1996 John W. Eaton
###
### This file is part of Octave.
###
### Octave is free software; you can redistribute it and/or modify it
### under the terms of the GNU General Public License as published by
### the Free Software Foundation; either version 2, or (at your option)
### any later version.
###
### Octave is distributed in the hope that it will be useful, but
### WITHOUT ANY WARRANTY; without even the implied warranty of
### MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
### General Public License for more details.
###
### You should have received a copy of the GNU General Public License
### along with Octave; see the file COPYING.  If not, write to the Free
### Software Foundation, 59 Temple Place - Suite 330, Boston, MA
### 02111-1307, USA.

## usage: beta (a, b)
##
## Returns the beta function beta(a,b) = gamma(a) * gamma(b) / gamma(a+b)
## of a and b.

## Author: KH <Kurt.Hornik@ci.tuwien.ac.at>
## Created: 13 June 1993
## Adapted-By: jwe

function retval = beta (a, b)
  
  if (nargin != 2)
    usage ("beta (a, b)");
  endif

  retval = exp (lgamma (a) + lgamma (b) - lgamma (a+b));

endfunction