# include <math.h>
# include <stdio.h>
# include <stdlib.h>
# include <time.h>

# include "zero_chandrupatla.h"

int main ( );
void zero_chandrupatla_example ( double f ( double x ), double a, double b, 
  char *title );
double f_01 ( double x );
double f_02 ( double x );
double f_03 ( double x );
double f_04 ( double x );
double f_05 ( double x );
double f_06 ( double x );
double f_07 ( double x );
double f_08 ( double x );
double f_09 ( double x );
void timestamp ( );

/******************************************************************************/

int main ( )

/******************************************************************************/
/*
  Purpose:

    zero_chandrupatla_test() tests zero_chandrupatla().

  Licensing:

    This code is distributed under the MIT license.

  Modified:

    19 March 2024

  Author:

    John Burkardt
*/
{
  double a;
  double b;
  char *title;

  timestamp ( );
  printf ( "\n" );
  printf ( "zero_chandrupatla_test():\n" );
  printf ( "  C version\n" );
  printf ( "  zero_chandrupatla() seeks a root of a function f(x)\n" );
  printf ( "  in an interval [a,b].\n" );

  a = 2.0;
  b = 3.0;
  title = "f_01(x) = x^3 - 2 x - 5";
  zero_chandrupatla_example ( f_01, a, b, title );

  a = 0.5;
  b = 1.51;
  title = "f_02(x) = 1 - 1/x^2";
  zero_chandrupatla_example ( f_02, a, b, title );

  a = 0.0;
  b = 5.0;
  title = "f_03(x) = ( x - 3 )^3";
  zero_chandrupatla_example ( f_03, a, b, title );

  a = 0.0;
  b = 5.0;
  title = "f_04(x) = 6 * ( x - 2 )^5";
  zero_chandrupatla_example ( f_04, a, b, title );

  a = -1.0;
  b = 4.0;
  title = "f_05(x) = x^9";
  zero_chandrupatla_example ( f_05, a, b, title );

  a = -1.0;
  b = 4.0;
  title = "f_06(x) = x^19";
  zero_chandrupatla_example ( f_06, a, b, title );

  a = -1.0;
  b = 4.0;
  title = "f_07(x) = x e^(-1/x2)";
  zero_chandrupatla_example ( f_07, a, b, title );

  a = 0.0002;
  b = 2.0;
  title = "f_08(x) = -(3062(1-xi)e^(-x)/(xi+(1-xi)e^(-x)) - 1013 + 1628/x";
  zero_chandrupatla_example ( f_08, a, b, title );

  a = 0.0002;
  b = 1.0;
  title = "f_09(x) = e^x - 2 - 0.01/x^2 + 0.000002/x^3";
  zero_chandrupatla_example ( f_09, a, b, title );
/*
  Terminate.
*/
  printf ( "\n" );
  printf ( "zero_chandrupatla_test():\n" );
  printf ( "  Normal end of execution.\n" );
  printf ( "\n" );
  timestamp ( );

  return 0;
}
/******************************************************************************/

void zero_chandrupatla_example ( double f ( double x ), double a, double b, 
  char *title )

/******************************************************************************/
/*
  Purpose:

    zero_chandrupatla_example() tests zero_chandrupatla() on a test function.

  Licensing:

    This code is distributed under the MIT license.

  Modified:

    19 March 2024

  Author:

    John Burkardt

  Input:

    double f ( double x ): the user-supplied function.

    double a, b: the endpoints of the change of sign interval.

    char *title: a title for the problem.
*/
{
  double fa;
  double fb;
  double fz;
  int calls;
  double z;

  zero_chandrupatla ( f, a, b, &z, &fz, &calls );

  fz = f ( z );
  fa = f ( a );
  fb = f ( b );

  printf ( "\n" );
  printf ( "  %s\n", title );
  printf ( "\n" );
  printf ( "      A                 Z             B\n" );
  printf ( "    F(A)              F(Z)          F(B)\n" );
  printf ( "\n" );
  printf ( "  %14f  %14f  %14f\n", a,  z,  b );
  printf ( "  %14e  %14e  %14e\n", fa, fz, fb );
  printf ( "  Number of calls to F = %d\n", calls );

  return;
}
/******************************************************************************/

double f_01 ( double x )

/******************************************************************************/
/*
  Purpose:

    f_01() evaluates test function 1.
*/
{
  double fx;

  fx = x * x * x - 2.0 * x - 5.0;

  return fx;
}
/******************************************************************************/

double f_02 ( double x )

/******************************************************************************/
/*
  Purpose:

    f_02() evaluates test function 2.
*/
{
  double fx;

  fx = 1.0 - 1.0 / x / x;

  return fx;
}
/******************************************************************************/

double f_03 ( double x )

/******************************************************************************/
/*
  Purpose:

    f_03() evaluates test function 3.
*/
{
  double fx;

  fx = pow ( x - 3.0, 3 );

  return fx;
}
/******************************************************************************/

double f_04 ( double x )

/******************************************************************************/
/*
  Purpose:

    f_04() evaluates test function 4.
*/
{
  double fx;

  fx = 6.0 * pow ( x - 2.0, 5 );

  return fx;
}
/******************************************************************************/

double f_05 ( double x )

/******************************************************************************/
/*
  Purpose:

    f_05() evaluates test function 5.
*/
{
  double fx;

  fx = pow ( x, 9 );

  return fx;
}
/******************************************************************************/

double f_06 ( double x )

/******************************************************************************/
/*
  Purpose:

    f_06() evaluates test function 6.
*/
{
  double fx;

  fx = pow ( x, 19 );

  return fx;
}
/******************************************************************************/

double f_07 ( double x )

/******************************************************************************/
/*
  Purpose:

    f_07() evaluates test function 7.
*/
{
  double fx;

  if ( fabs ( x ) < 3.8E-04 )
  {
    fx = 0.0;
  }
  else
  {
    fx = x * exp ( - ( 1.0 / x / x ) );
  }

  return fx;
}
/******************************************************************************/

double f_08 ( double x )

/******************************************************************************/
/*
  Purpose:

    f_08() evaluates test function 8.
*/
{
  double bot;
  double fx;
  double top;
  double xi;

  xi = 0.61489;
  top = ( 3062.0 * ( 1.0 - xi ) * exp ( - x ) );
  bot = ( xi + ( 1.0 - xi ) * exp ( - x ) );

  fx = - top / bot - 1013.0 + 1628.0 / x;

  return fx;
}
/******************************************************************************/

double f_09 ( double x )

/******************************************************************************/
/*
  Purpose:

    f_09() evaluates test function 9.
*/
{
  double fx;

  fx = exp ( x ) - 2.0 - 0.01 / x / x + 0.000002 / x / x / x;

  return fx;
}
/******************************************************************************/

void timestamp ( )

/******************************************************************************/
/*
  Purpose:

    timestamp() prints the current YMDHMS date as a time stamp.

  Example:

    17 June 2014 09:45:54 AM

  Licensing:

    This code is distributed under the MIT license. 

  Modified:

    01 May 2021

  Author:

    John Burkardt
*/
{
# define TIME_SIZE 40

  static char time_buffer[TIME_SIZE];
  const struct tm *tm;
  time_t now;

  now = time ( NULL );
  tm = localtime ( &now );

  strftime ( time_buffer, TIME_SIZE, "%d %B %Y %I:%M:%S %p", tm );

  printf ( "%s\n", time_buffer );

  return;
# undef TIME_SIZE
}