Provided by: pdl_2.4.7+dfsg-2ubuntu5_amd64 #### 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);

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}]);

```

#### SEEALSO

```       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
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.
```