multidimensional

MROOT(3)						User Contributed Perl Documentation						  MROOT(3)

NAME

       PDL::GSL::MROOT - PDL interface to multidimensional root-finding routines in GSL

DESCRIPTION

       This is an interface to the multidimensional root-finding package present in the GNU Scientific Library.

       At the moment there is a single function gslmroot_fsolver which provides an interface to the algorithms in the GSL library that do not use
       derivatives.

SYNOPSIS

	  use PDL;
	  use PDL::GSL::MROOT;

	  my $init = pdl (-10.00, -5.0);
	  my $epsabs = 1e-7;

	 $res = gslmroot_fsolver($init, &rosenbrock,
				 {Method => 0, EpsAbs => $epsabs});

	 sub rosenbrock{
	    my ($x) = @_;
	    my $a = 1;
	    my $b = 10;
	    my $y = zeroes($x);
	    $y->slice(0) .=  $a * (1 - $x->slice(0));
	    $y->slice(1) .=  $b * ($x->slice(1) - $x->slice(0)**2);
	    return $y;
	 }

FUNCTIONS

   gslmroot_fsolver -- Multidimensional root finder without using derivatives
       This function provides an interface to the multidimensional root finding algorithms in the GSL library. It takes a minimum of two
       argumennts: a piddle $init with an initial guess for the roots of the system and a reference to a function. The latter function must return
       a piddle whose i-th element is the i-th equation evaluated at the vector x (a piddle which is the sole input to this function). See the
       example in the Synopsis above for an illustration. The function returns a piddle with the roots for the system of equations.

       Two optional arguments can be specified as shown below. One is Method, which can take the values 0,1,2,3. They correspond to the 'hybrids',
       'hybrid', 'dnewton' and 'broyden' algorithms respectively (see GSL documentation for details). The other optional argument is Epsabs, which
       sets the absolute accuracy to which the roots of the system of equations are required. The default value for Method is 0 ('hybrids'
       algorithm) and the default for Epsabs is 1e-3.

       Usage:

	  $res = gslmroot_fsolver($init, $function_ref,
				  [{Method => $method, Epsabs => $epsabs}]);

SEE ALSO

       PDL

       The GSL documentation is online at

	 http://sources.redhat.com/gsl/ref/gsl-ref_toc.html

AUTHOR

       This file copyright (C) 2006 Andres Jordan <ajordan@eso.org> and Simon Casassus <simon@das.uchile.cl> All rights reserved. There is no
       warranty. You are allowed to redistribute this software/documentation under certain conditions. For details, see the file COPYING in the
       PDL distribution. If this file is separated from the PDL distribution, the copyright notice should be included in the file.

FUNCTIONS

   fsolver_meat
	 Signature: (double  xfree(n);	 double epsabs(); int method(); SV* funcion1)

       info not available

       fsolver_meat does not process bad values.  It will set the bad-value flag of all output piddles if the flag is set for any of the input
       piddles.

perl v5.12.1							    2010-07-05								  MROOT(3)