/* min/test_funcs.c

 * 

 * Copyright (C) 1996, 1997, 1998, 1999, 2000, 2007 Brian Gough

 * 

 * This program 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 3 of the License, or (at

 * your option) any later version.

 * 

 * This program 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 this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

 */

#include <gsl/gsl_math.h>

#include <gsl/gsl_min.h>

#include "test.h"

gsl_function create_function (double (*f)(double, void *)) 

{

  gsl_function F ;

  F.function = f ;

  F.params = 0 ;

  return F ;

}

double

f_cos (double x, void * p)

{

  p = 0;  /* avoid warning about unused parameter */

  return cos(x);

}

/* f(x) = x^4 - 1 */

/* minimum at x = 0 */

double

func1 (double x, void * p)

{

  p = 0;  /* avoid warning about unused parameter */

  return pow (x, 4.0) - 1;

}

/* f(x) = sqrt(|x|) */

/* minimum at x = 0 */

double

func2 (double x, void * p)

{

  p = 0;  /* avoid warning about unused parameter */

  return sqrt(fabs(x));

}

/* f(x) = 1 for x < 1 and -exp(-x) for x >= 1 */

/* minimum at x = 1 */

double

func3 (double x, void * p)

{

  p = 0;  /* avoid warning about unused parameter */

  if (x < 1)

    return 1 ;

  else

    return - exp(-x) ;

}

/* f(x) = x - 30/(1+1e5*(x-0.8)**2) */

/* minimum near x = 0.8 */

double

func4 (double x, void * p)

{

  p = 0;  /* avoid warning about unused parameter */

  return x - 30.0 / (1.0 + 1e5 * pow(x-0.8, 2.0));

}