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fsolve.cc
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1997-05-26
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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.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <string>
#include <iostream.h>
#include "NLEqn.h"
#include "defun-dld.h"
#include "error.h"
#include "gripes.h"
#include "help.h"
#include "pager.h"
#include "pt-fvc.h"
#include "oct-obj.h"
#include "utils.h"
#include "variables.h"
// Global pointer for user defined function required by hybrd1.
static tree_fvc *fsolve_fcn;
static NLEqn_options fsolve_opts;
int
hybrd_info_to_fsolve_info (int info)
{
switch (info)
{
case -1:
info = -2;
break;
case 0:
info = -1;
break;
case 1:
break;
case 2:
info = 4;
break;
case 3:
case 4:
case 5:
info = 3;
break;
default:
panic_impossible ();
break;
}
return info;
}
ColumnVector
fsolve_user_function (const ColumnVector& x)
{
ColumnVector retval;
int n = x.capacity ();
octave_value_list args;
args.resize (1);
if (n > 1)
{
Matrix m (n, 1);
for (int i = 0; i < n; i++)
m (i, 0) = x (i);
octave_value vars (m);
args(0) = vars;
}
else
{
double d = x (0);
octave_value vars (d);
args(0) = vars;
}
if (fsolve_fcn)
{
octave_value_list tmp = fsolve_fcn->eval (0, 1, args);
if (tmp.length () > 0 && tmp(0).is_defined ())
{
retval = tmp(0).vector_value ();
if (error_state || retval.length () <= 0)
gripe_user_supplied_eval ("fsolve");
}
else
gripe_user_supplied_eval ("fsolve");
}
return retval;
}
DEFUN_DLD (fsolve, args, nargout,
"Solve nonlinear equations using Minpack. Usage:\n\
\n\
[X, INFO] = fsolve (F, X0)\n\
\n\
Where the first argument is the name of the function to call to\n\
compute the vector of function values. It must have the form\n\
\n\
y = f (x)\n\
\n\
where y and x are vectors.")
{
octave_value_list retval;
int nargin = args.length ();
if (nargin != 2 || nargout > 3)
{
print_usage ("fsolve");
return retval;
}
fsolve_fcn = is_valid_function (args(0), "fsolve", 1);
if (! fsolve_fcn)
return retval;
ColumnVector x = args(1).vector_value ();
if (error_state)
{
error ("fsolve: expecting vector as second argument");
return retval;
}
if (nargin > 2)
warning ("fsolve: ignoring extra arguments");
if (nargout > 2)
warning ("fsolve: can't compute path output yet");
NLFunc foo_fcn (fsolve_user_function);
NLEqn foo (x, foo_fcn);
foo.set_options (fsolve_opts);
int info;
ColumnVector soln = foo.solve (info);
info = hybrd_info_to_fsolve_info (info);
retval.resize (nargout ? nargout : 1);
retval(0) = soln, 1;
if (nargout > 1)
retval(1) = (double) info;
return retval;
}
typedef void (NLEqn_options::*d_set_opt_mf) (double);
typedef double (NLEqn_options::*d_get_opt_mf) (void);
#define MAX_TOKENS 1
struct NLEQN_OPTIONS
{
const char *keyword;
const char *kw_tok[MAX_TOKENS + 1];
int min_len[MAX_TOKENS + 1];
int min_toks_to_match;
d_set_opt_mf d_set_fcn;
d_get_opt_mf d_get_fcn;
};
static NLEQN_OPTIONS fsolve_option_table [] =
{
{ "tolerance",
{ "tolerance", 0, },
{ 1, 0, }, 1,
NLEqn_options::set_tolerance,
NLEqn_options::tolerance, },
{ 0,
{ 0, 0, },
{ 0, 0, }, 0,
0, 0, },
};
static void
print_fsolve_option_list (ostream& os)
{
print_usage ("fsolve_options", 1);
os << "\n"
<< "Options for fsolve include:\n\n"
<< " keyword value\n"
<< " ------- -----\n\n";
NLEQN_OPTIONS *list = fsolve_option_table;
const char *keyword;
while ((keyword = list->keyword) != 0)
{
os.form (" %-40s ", keyword);
double val = (fsolve_opts.*list->d_get_fcn) ();
if (val < 0.0)
os << "computed automatically";
else
os << val;
os << "\n";
list++;
}
os << "\n";
}
static void
set_fsolve_option (const string& keyword, double val)
{
NLEQN_OPTIONS *list = fsolve_option_table;
while (list->keyword != 0)
{
if (keyword_almost_match (list->kw_tok, list->min_len, keyword,
list->min_toks_to_match, MAX_TOKENS))
{
(fsolve_opts.*list->d_set_fcn) (val);
return;
}
list++;
}
warning ("fsolve_options: no match for `%s'", keyword.c_str ());
}
static octave_value_list
show_fsolve_option (const string& keyword)
{
octave_value_list retval;
NLEQN_OPTIONS *list = fsolve_option_table;
while (list->keyword != 0)
{
if (keyword_almost_match (list->kw_tok, list->min_len, keyword,
list->min_toks_to_match, MAX_TOKENS))
{
return (fsolve_opts.*list->d_get_fcn) ();
}
list++;
}
warning ("fsolve_options: no match for `%s'", keyword.c_str ());
return retval;
}
DEFUN_DLD (fsolve_options, args, ,
"fsolve_options (KEYWORD, VALUE)\n\
\n\
Set or show options for fsolve. Keywords may be abbreviated\n\
to the shortest match.")
{
octave_value_list retval;
int nargin = args.length ();
if (nargin == 0)
{
print_fsolve_option_list (octave_stdout);
return retval;
}
else if (nargin == 1 || nargin == 2)
{
string keyword = args(0).string_value ();
if (! error_state)
{
if (nargin == 1)
return show_fsolve_option (keyword);
else
{
double val = args(1).double_value ();
if (! error_state)
{
set_fsolve_option (keyword, val);
return retval;
}
}
}
}
print_usage ("fsolve_options");
return retval;
}
/*
;;; Local Variables: ***
;;; mode: C++ ***
;;; End: ***
*/