MROOT(3) User Contributed Perl Documentation MROOT(3)NAMEPDL::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);
my $y0 = $y->slice(0);
$y0 .= $a * (1 - $x->slice(0));
my $y1 = $y->slice(1);
$y1 .= $b * ($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://www.gnu.org/software/gsl/manual/
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 v5.18.1 2014-01-17 MROOT(3)
