1MROOT(3)              User Contributed Perl Documentation             MROOT(3)
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NAME

6       PDL::GSL::MROOT - PDL interface to multidimensional root-finding
7       routines in GSL
8

DESCRIPTION

10       This is an interface to the multidimensional root-finding package
11       present in the GNU Scientific Library.
12
13       At the moment there is a single function gslmroot_fsolver which
14       provides an interface to the algorithms in the GSL library that do not
15       use derivatives.
16

SYNOPSIS

18          use PDL;
19          use PDL::GSL::MROOT;
20
21          my $init = pdl (-10.00, -5.0);
22          my $epsabs = 1e-7;
23
24
25         $res = gslmroot_fsolver($init, \&rosenbrock,
26                                 {Method => 0, EpsAbs => $epsabs});
27
28
29         sub rosenbrock{
30            my ($x) = @_;
31            my $a = 1;
32            my $b = 10;
33            my $y = zeroes($x);
34            $y->slice(0) .=  $a * (1 - $x->slice(0));
35            $y->slice(1) .=  $b * ($x->slice(1) - $x->slice(0)**2);
36            return $y;
37         }
38

FUNCTIONS

40   gslmroot_fsolver -- Multidimensional root finder without using derivatives
41       This function provides an interface to the multidimensional root
42       finding algorithms in the GSL library. It takes a minimum of two
43       argumennts: a piddle $init with an initial guess for the roots of the
44       system and a reference to a function. The latter function must return a
45       piddle whose i-th element is the i-th equation evaluated at the vector
46       x (a piddle which is the sole input to this function). See the example
47       in the Synopsis above for an illustration. The function returns a
48       piddle with the roots for the system of equations.
49
50       Two optional arguments can be specified as shown below. One is Method,
51       which can take the values 0,1,2,3. They correspond to the 'hybrids',
52       'hybrid', 'dnewton' and 'broyden' algorithms respectively (see GSL
53       documentation for details). The other optional argument is Epsabs,
54       which sets the absolute accuracy to which the roots of the system of
55       equations are required. The default value for Method is 0 ('hybrids'
56       algorithm) and the default for Epsabs is 1e-3.
57
58       Usage:
59
60          $res = gslmroot_fsolver($init, $function_ref,
61                                  [{Method => $method, Epsabs => $epsabs}]);
62

SEE ALSO

64       PDL
65
66       The GSL documentation is online at
67
68         http://sources.redhat.com/gsl/ref/gsl-ref_toc.html
69

AUTHOR

71       This file copyright (C) 2006 Andres Jordan <ajordan@eso.org> and Simon
72       Casassus <simon@das.uchile.cl> All rights reserved. There is no
73       warranty. You are allowed to redistribute this software/documentation
74       under certain conditions. For details, see the file COPYING in the PDL
75       distribution. If this file is separated from the PDL distribution, the
76       copyright notice should be included in the file.
77

FUNCTIONS

79   fsolver_meat
80         Signature: (double  xfree(n);   double epsabs(); int method(); SV* funcion1)
81
82       info not available
83
84       fsolver_meat does not process bad values.  It will set the bad-value
85       flag of all output piddles if the flag is set for any of the input
86       piddles.
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90perl v5.12.3                      2011-03-31                          MROOT(3)
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