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

int main ( int argc, char *argv[] );
char ch_cap ( char ch );
int ch_eqi ( char ch1, char ch2 );
int ch_to_digit ( char ch );
void gmsh_data_read ( char *gmsh_filename, int node_dim, int node_num, 
  double node_x[], int element_order, int element_num, int element_node[] );
void gmsh_size_read ( char *gmsh_filename, int *node_num, int *node_dim,
  int *element_num, int *element_order );
void i4mat_write ( char *output_filename, int m, int n, int table[] );
void r8mat_write ( char *output_filename, int m, int n, double table[] );
int s_begin ( char *s1, char *s2 );
int s_len_trim ( char *s );
int s_to_i4 ( char *s, int *last, int *error );
double s_to_r8 ( char *s, int *lchar, int *error );
void timestamp ( );

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

int main ( int argc, char *argv[] )

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

    MAIN is the main program for GMSH_TO_FEM.

  Discussion:

    GMSH_TO_FEM converts mesh data from GMSH to FEM format.

  Usage:

    gmsh_to_fem prefix

    where 'prefix' is the common filename prefix:

    * 'prefix'.msh contains the GMSH mesh file.
    * 'prefix'_nodes.txt will contain the node coordinates.
    * 'prefix'_elements.txt will contain the element node connectivity.

  Licensing:

    This code is distributed under the MIT license. 

  Modified:

    20 October 2014

  Author:

    John Burkardt
*/
{
  int *element_node;
  int element_num;
  int element_order;
  char fem_element_filename[255];
  char fem_node_filename[255];
  char gmsh_filename[255];
  int m;
  int node_num;
  double *node_x;
  char prefix[255];

  timestamp ( );
  printf ( "\n" );
  printf ( "GMSH_TO_FEM\n" );
  printf ( "  C version:\n" );
  printf ( "  Read a mesh description created by GMSH:\n" );
  printf ( "  * \"prefix\".msh, the GMSH mesh file.\n" );
  printf ( "  Write out two simple FEM files listing nodes and elements.\n" );
  printf ( "  * \"prefix\"_nodes.txt, node coordinates.\n" );
  printf ( "  * \"prefix\"_elements.txt, element connectivity.\n" );
/*
  Get the filename prefix.
*/
  if ( argc <= 1 ) 
  {
    printf ( "\n" );
    printf ( "  Please enter the filename prefix.\n" );

    scanf ( "%s", prefix );
  }
  else 
  {
    strcpy ( prefix, argv[1] );
  }
/*
  Create the filenames.
*/
  strcpy ( gmsh_filename, prefix );
  strcat ( gmsh_filename, ".msh" );
  strcpy ( fem_node_filename, prefix );
  strcat ( fem_node_filename, "_nodes.txt" );
  strcpy ( fem_element_filename, prefix );
  strcat ( fem_element_filename, "_elements.txt" );
/*
  Read GMSH sizes.
*/
  gmsh_size_read ( gmsh_filename, &node_num, &m, &element_num, &element_order );
/*
  Report sizes.
*/
  printf ( "\n" );
  printf ( "  Size information from GMSH:\n" );
  printf ( "  Spatial dimension M = %d\n", m );
  printf ( "  Number of nodes NODE_NUM = %d\n", node_num );
  printf ( "  Number of elements ELEMENT_NUM = %d\n", element_num );
  printf ( "  Element order ELEMENT_ORDER = %d\n", element_order );
/*
  Allocate memory.
*/
  node_x = ( double * ) malloc ( m * node_num * sizeof ( double ) );
  element_node = ( int * ) 
    malloc ( element_order * element_num * sizeof ( int ) );
/*
  Read GMSH data.
*/
  gmsh_data_read ( gmsh_filename, m, node_num, node_x, element_order, 
    element_num, element_node );
/*
  Write FEM data.
*/
  r8mat_write ( fem_node_filename, m, node_num, node_x );

  i4mat_write ( fem_element_filename, element_order, element_num, 
    element_node );
/*
  Free memory.
*/
  free ( element_node );
  free ( node_x );
/*
  Terminate.
*/
  printf ( "\n" );
  printf ( "GMSH_TO_FEM:\n" );
  printf ( "  Normal end of execution.\n" );
  printf ( "\n" );
  timestamp ( );

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

char ch_cap ( char ch )

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

    CH_CAP capitalizes a single character.

  Discussion:

    This routine should be equivalent to the library "toupper" function.

  Licensing:

    This code is distributed under the MIT license. 

  Modified:

    19 July 1998

  Author:

    John Burkardt

  Parameters:

    Input, char CH, the character to capitalize.

    Output, char CH_CAP, the capitalized character.
*/
{
  if ( 97 <= ch && ch <= 122 ) 
  {
    ch = ch - 32;
  }   

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

int ch_eqi ( char ch1, char ch2 )

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

    CH_EQI is TRUE (1) if two characters are equal, disregarding case.

  Licensing:

    This code is distributed under the MIT license. 

  Modified:

    13 June 2003

  Author:

    John Burkardt

  Parameters:

    Input, char CH1, CH2, the characters to compare.

    Output, int CH_EQI, is TRUE (1) if the two characters are equal,
    disregarding case and FALSE (0) otherwise.
*/
{
  int value;

  if ( 97 <= ch1 && ch1 <= 122 ) 
  {
    ch1 = ch1 - 32;
  } 
  if ( 97 <= ch2 && ch2 <= 122 ) 
  {
    ch2 = ch2 - 32;
  }     
  if ( ch1 == ch2 )
  {
    value = 1;
  }
  else
  {
    value = 0;
  }
  return value;
}
/******************************************************************************/

int ch_to_digit ( char ch )

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

    CH_TO_DIGIT returns the integer value of a base 10 digit.

  Example:

     CH  DIGIT
    ---  -----
    '0'    0
    '1'    1
    ...  ...
    '9'    9
    ' '    0
    'X'   -1

  Licensing:

    This code is distributed under the MIT license. 

  Modified:

    13 June 2003

  Author:

    John Burkardt

  Parameters:

    Input, char CH, the decimal digit, '0' through '9' or blank are legal.

    Output, int CH_TO_DIGIT, the corresponding integer value.  If the 
    character was 'illegal', then DIGIT is -1.
*/
{
  int digit;

  if ( '0' <= ch && ch <= '9' )
  {
    digit = ch - '0';
  }
  else if ( ch == ' ' )
  {
    digit = 0;
  }
  else
  {
    digit = -1;
  }

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

void gmsh_data_read ( char *gmsh_filename, int node_dim, int node_num, 
  double node_x[], int element_order, int element_num, int element_node[] )

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

    GMSH_DATA_READ reads data from a GMSH file.

  Licensing:

    This code is distributed under the MIT license.

  Modified:

    20 October 2014

  Author:

    John Burkardt

  Parameters:

    Input, character *GMSH_FILENAME, the GMSH filename.

    Input, int NODE_DIM, the spatial dimension.

    Input, int NODE_NUM, the number of nodes.

    Input, double NODE_X[NODE_DIM*NODE_NUM], the node coordinates.

    Input, int ELEMENT_ORDER, the order of the elements.

    Input, int ELEMENT_NUM, the number of elements.

    Input, int ELEMENT_NODE[ELEMENT_ORDER*ELEMENT_NUM], 
    the nodes that make up each element.
*/
{
  char *error;
  int i;
  int ierror;
  FILE *input;
  int j;
  int k;
  int length;
  int level;
  char text[255];
  char* text_pointer;
  double x;

  input = fopen ( gmsh_filename, "rt" );

  if ( ! input )
  {
    fprintf ( stderr, "\n" );
    fprintf ( stderr, "GMSH_DATA_READ - Fatal error!\n" );
    fprintf ( stderr, "  Could not open input file \"%s\"\n", gmsh_filename );
    exit ( 1 );
  }

  level = 0;
 
  for ( ; ; )
  {
    text_pointer = text;
    error = fgets ( text_pointer, 255, input );

    if ( !error )
    {
      break;
    }

    if ( level == 0 )
    {
      if ( s_begin ( text_pointer, "$Nodes" ) )
      {
        level = 1;
        j = 0;
      }
    }
    else if ( level == 1 )
    {
      s_to_i4 ( text_pointer, &length, &ierror );
      level = 2;
    }
    else if ( level == 2 )
    {
      if ( s_begin ( text_pointer, "$EndNodes" ) )
      {
        break;
      }
      else
      {
        s_to_i4 ( text_pointer, &length, &ierror );
        text_pointer = text_pointer + length;
        for ( i = 0; i < node_dim; i++ )
        {
          x = s_to_r8 ( text_pointer, &length, &ierror );
          text_pointer = text_pointer + length;
          node_x[i+j*node_dim] = x;
        }
        j = j + 1;
      }
    }
  }
/*
  Now read element information.
*/
  level = 0;

  for ( ; ; )
  {
    text_pointer = text;
    error = fgets ( text_pointer, 255, input );

    if ( !error )
    {
      break;
    }

    if ( level == 0 )
    {
      if ( s_begin ( text_pointer, "$Elements" ) )
      {
        level = 1;
        j = 0;
      }
    }
    else if ( level == 1 )
    {
      s_to_i4 ( text_pointer, &length, &ierror );
      level = 2;
    }
    else if ( level == 2 )
    {
      if ( s_begin ( text_pointer, "$EndElements" ) )
      {
        break;
      }
      else
      {
        for ( k = 1; k <= 5; k++ )
        {
          s_to_i4 ( text_pointer, &length, &ierror );
          text_pointer = text_pointer + length;
        }
        for ( i = 0; i < element_order; i++ )
        {
          k = s_to_i4 ( text_pointer, &length, &ierror );
          text_pointer = text_pointer + length;
          element_node[i+j*element_order] = k;
        }
        j = j + 1;
      }
    }
  }

  fclose ( input );

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

void gmsh_size_read ( char *gmsh_filename, int *node_num, int *node_dim,
  int *element_num, int *element_order )

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

    GMSH_SIZE_READ reads sizes from a GMSH file.

  Licensing:

    This code is distributed under the MIT license.

  Modified:

    19 October 2014

  Author:

    John Burkardt

  Parameters:

    Input, character *GMSH_FILENAME, the GMSH filename.

    Output, int *NODE_NUM, the number of nodes.

    Output, int *NODE_DIM, the spatial dimension.

    Output, int *ELEMENT_NUM, the number of elements.

    Output, int *ELEMENT_ORDER, the order of the elements.
*/
{
  char *error;
  int ierror;
  FILE *input;
  int k;
  int length;
  int level;
  const double r8_big = 1.0E+30;
  char text[255];
  char* text_pointer;
  double x;
  double x_max;
  double x_min;
  double y;
  double y_max;
  double y_min;
  double z;
  double z_max;
  double z_min;

  *node_num = 0;
  *node_dim = 0;

  x_max = - r8_big;
  x_min = + r8_big;
  y_max = - r8_big;
  y_min = + r8_big;
  z_max = - r8_big;
  z_min = + r8_big;

  input = fopen ( gmsh_filename, "rt" );

  if ( ! input )
  {
    fprintf ( stderr, "\n" );
    fprintf ( stderr, "GMSH_SIZE_READ - Fatal error!\n" );
    fprintf ( stderr, "  Could not open input file \"%s\"\n", gmsh_filename );
    exit ( 1 );
  }

  level = 0;
 
  for ( ; ; )
  {
    text_pointer = text;
    error = fgets ( text_pointer, 255, input );

    if ( !error )
    {
      break;
    }

    if ( level == 0 )
    {
      if ( s_begin ( text_pointer, "$Nodes" ) )
      {
        level = 1;
      }
    }
    else if ( level == 1 )
    {
      *node_num = s_to_i4 ( text_pointer, &length, &ierror );
      level = 2;
    }
    else if ( level == 2 )
    {
      if ( s_begin ( text_pointer, "$EndNodes" ) )
      {
        break;
      }
      else
      {
        s_to_i4 ( text_pointer, &length, &ierror );
        text_pointer = text_pointer + length;
        x = s_to_r8 ( text_pointer, &length, &ierror );
        x_min = fmin ( x_min, x );
        x_max = fmax ( x_max, x );
        text_pointer = text_pointer + length;
        y = s_to_r8 ( text_pointer, &length, &ierror );
        y_min = fmin ( y_min, y );
        y_max = fmax ( y_max, y );
        text_pointer = text_pointer + length;
        z = s_to_r8 ( text_pointer, &length, &ierror);
        text_pointer = text_pointer + length;
        z_min = fmin ( z_min, z );
        z_max = fmax ( z_max, z );
      }
    }
  }
/*
  Make a very simple guess as to the dimensionality of the data.
*/
  *node_dim = 3;
  if ( z_max == z_min )
  {
    *node_dim = 2;
    if ( y_max == y_min )
    {
      *node_dim = 1;
    }
  }
/*
  Now read element information.
*/
  level = 0;

  for ( ; ; )
  {
    text_pointer = text;
    error = fgets ( text_pointer, 255, input );

    if ( !error )
    {
      break;
    }

    if ( level == 0 )
    {
      if ( s_begin ( text_pointer, "$Elements" ) )
      {
        level = 1;
      }
    }
    else if ( level == 1 )
    {
      *element_num = s_to_i4 ( text_pointer, &length, &ierror );
      level = 2;
    }
    else if ( level == 2 )
    {
      if ( s_begin ( text_pointer, "$EndElements" ) )
      {
        break;
      }
      else
      {
        k = 0;
        for ( ; ; )
        {
          s_to_i4 ( text_pointer, &length, &ierror );
          text_pointer = text_pointer + length;
          if ( ierror != 0 )
          {
            break;
          }
          k = k + 1;
        }
        *element_order = k - 5;
        break;
      }
    }
  }

  fclose ( input );

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

void i4mat_write ( char *output_filename, int m, int n, int table[] )

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

    I4MAT_WRITE writes an I4MAT file.

  Discussion:

    An I4MAT is an array of I4's.

  Licensing:

    This code is distributed under the MIT license. 

  Modified:

    01 June 2009

  Author:

    John Burkardt

  Parameters:

    Input, char *OUTPUT_FILENAME, the output filename.

    Input, int M, the spatial dimension.

    Input, int N, the number of points.

    Input, int TABLE[M*N], the data.
*/
{
  int i;
  int j;
  FILE *output;
/*
  Open the file.
*/
  output = fopen ( output_filename, "wt" );

  if ( !output )
  {
    fprintf ( stderr, "\n" );
    fprintf ( stderr, "I4MAT_WRITE - Fatal error!\n" );
    fprintf ( stderr, "  Could not open the file \"%s\".\n", output_filename );
    exit ( 1 );
  }
/*
  Write the data.
*/
  for ( j = 0; j < n; j++ )
  {
    for ( i = 0; i < m; i++ )
    {
      fprintf ( output, "  %d", table[i+j*m] );
    }
    fprintf ( output, "\n" );
  }
/*
  Close the file.
*/
  fclose ( output );

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

void r8mat_write ( char *output_filename, int m, int n, double table[] )

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

    R8MAT_WRITE writes an R8MAT file.

  Discussion:

    An R8MAT is an array of R8's.

  Licensing:

    This code is distributed under the MIT license. 

  Modified:

    01 June 2009

  Author:

    John Burkardt

  Parameters:

    Input, char *OUTPUT_FILENAME, the output filename.

    Input, int M, the spatial dimension.

    Input, int N, the number of points.

    Input, double TABLE[M*N], the data.
*/
{
  int i;
  int j;
  FILE *output;
/*
  Open the file.
*/
  output = fopen ( output_filename, "wt" );

  if ( !output )
  {
    fprintf ( stderr, "\n" );
    fprintf ( stderr, "R8MAT_WRITE - Fatal error!\n" );
    fprintf ( stderr, 
      "  Could not open the output file \"%s\".\n", output_filename );
    exit ( 1 );
  }
/*
  Write the data.
*/
  for ( j = 0; j < n; j++ )
  {
    for ( i = 0; i < m; i++ )
    {
      fprintf ( output, "  %g", table[i+j*m] );
    }
    fprintf ( output, "\n" );
  }
/*
  Close the file.
*/
  fclose ( output );

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

int s_begin ( char *s1, char *s2 )

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

    S_BEGIN reports whether string 1 begins with string 2.

  Licensing:

    This code is distributed under the MIT license.

  Modified:

    22 November 2010

  Author:

    John Burkardt

  Parameters:

    Input, char *S1, char *S2, two strings.

    Output, int S_BEGIN, is true if S1 is the same as S2 up to
    the end of S2, and false otherwise.
*/
{
  int i;
  int n1;
  int n2;

  n1 = strlen ( s1 );
  n2 = strlen ( s2 );

  if ( n1 < n2 )
  {
    return 0;
  }

  for ( i = 0; i < n2; i++ )
  {
    if ( ch_cap ( s1[i] ) != ch_cap ( s2[i] ) )
    {
      return 0;
    }
  }
  return 1;
}
/******************************************************************************/

int s_len_trim ( char *s )

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

    S_LEN_TRIM returns the length of a string to the last nonblank.

  Discussion:

    It turns out that I also want to ignore the '\n' character!

  Licensing:

    This code is distributed under the MIT license.

  Modified:

    05 October 2014

  Author:

    John Burkardt

  Parameters:

    Input, char *S, a pointer to a string.

    Output, int S_LEN_TRIM, the length of the string to the last nonblank.
    If S_LEN_TRIM is 0, then the string is entirely blank.
*/
{
  int n;
  char *t;

  n = strlen ( s );
  t = s + strlen ( s ) - 1;

  while ( 0 < n )
  {
    if ( *t != ' ' && *t != '\n' )
    {
      return n;
    }
    t--;
    n--;
  }

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

int s_to_i4 ( char *s, int *last, int *error )

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

    S_TO_I4 reads an I4 from a string.

  Licensing:

    This code is distributed under the MIT license. 

  Modified:

    13 June 2003

  Author:

    John Burkardt

  Parameters:

    Input, char *S, a string to be examined.

    Output, int *LAST, the last character of S used to make IVAL.

    Output, int *ERROR is TRUE (1) if an error occurred and FALSE (0) otherwise.

    Output, int *S_TO_I4, the integer value read from the string.
    If the string is blank, then IVAL will be returned 0.
*/
{
  char c;
  int i;
  int isgn;
  int istate;
  int ival;

  *error = 0;
  istate = 0;
  isgn = 1;
  i = 0;
  ival = 0;

  while ( *s ) 
  {
    c = s[i];
    i = i + 1;
/*
  Haven't read anything.
*/
    if ( istate == 0 )
    {
      if ( c == ' ' )
      {
      }
      else if ( c == '-' )
      {
        istate = 1;
        isgn = -1;
      }
      else if ( c == '+' )
      {
        istate = 1;
        isgn = + 1;
      }
      else if ( '0' <= c && c <= '9' )
      {
        istate = 2;
        ival = c - '0';
      }
      else
      {
        *error = 1;
        return ival;
      }
    }
/*
  Have read the sign, expecting digits.
*/
    else if ( istate == 1 )
    {
      if ( c == ' ' )
      {
      }
      else if ( '0' <= c && c <= '9' )
      {
        istate = 2;
        ival = c - '0';
      }
      else
      {
        *error = 1;
        return ival;
      }
    }
/*
  Have read at least one digit, expecting more.
*/
    else if ( istate == 2 )
    {
      if ( '0' <= c && c <= '9' )
      {
        ival = 10 * (ival) + c - '0';
      }
      else
      {
        ival = isgn * ival;
        *last = i - 1;
        return ival;
      }

    }
  }
/*
  If we read all the characters in the string, see if we're OK.
*/
  if ( istate == 2 )
  {
    ival = isgn * ival;
    *last = s_len_trim ( s );
  }
  else
  {
    *error = 1;
    *last = 0;
  }

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

double s_to_r8 ( char *s, int *lchar, int *error )

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

    S_TO_R8 reads an R8 value from a string.

  Discussion:

    We have had some trouble with input of the form 1.0E-312.
    For now, let's assume anything less than 1.0E-20 is zero.

    This routine will read as many characters as possible until it reaches
    the end of the string, or encounters a character which cannot be
    part of the real number.

    Legal input is:

       1 blanks,
       2 '+' or '-' sign,
       2.5 spaces
       3 integer part,
       4 decimal point,
       5 fraction part,
       6 'E' or 'e' or 'D' or 'd', exponent marker,
       7 exponent sign,
       8 exponent integer part,
       9 exponent decimal point,
      10 exponent fraction part,
      11 blanks,
      12 final comma or semicolon.

    with most quantities optional.

  Example:

    S                 R

    '1'               1.0
    '     1   '       1.0
    '1A'              1.0
    '12,34,56'        12.0
    '  34 7'          34.0
    '-1E2ABCD'        -100.0
    '-1X2ABCD'        -1.0
    ' 2E-1'           0.2
    '23.45'           23.45
    '-4.2E+2'         -420.0
    '17d2'            1700.0
    '-14e-2'         -0.14
    'e2'              100.0
    '-12.73e-9.23'   -12.73 * 10.0^(-9.23)

  Licensing:

    This code is distributed under the MIT license. 

  Modified:

    24 June 2005

  Author:

    John Burkardt

  Parameters:

    Input, char *S, the string containing the
    data to be read.  Reading will begin at position 1 and
    terminate at the end of the string, or when no more
    characters can be read to form a legal real.  Blanks,
    commas, or other nonnumeric data will, in particular,
    cause the conversion to halt.

    Output, int *LCHAR, the number of characters read from
    the string to form the number, including any terminating
    characters such as a trailing comma or blanks.

    Output, int *ERROR, is TRUE (1) if an error occurred and FALSE (0)
    otherwise.

    Output, double S_TO_R8, the value that was read from the string.
*/
{
  char c;
  int ihave;
  int isgn;
  int iterm;
  int jbot;
  int jsgn;
  int jtop;
  int nchar;
  int ndig;
  double r;
  double rbot;
  double rexp;
  double rtop;
  char TAB = 9;

  nchar = s_len_trim ( s );
  *error = 0;
  r = 0.0;
  *lchar = -1;
  isgn = 1;
  rtop = 0.0;
  rbot = 1.0;
  jsgn = 1;
  jtop = 0;
  jbot = 1;
  ihave = 1;
  iterm = 0;

  for ( ; ; )
  {
    c = s[*lchar+1];
    *lchar = *lchar + 1;
/*
  Blank or TAB character.
*/
    if ( c == ' ' || c == TAB )
    {
      if ( ihave == 2 )
      {
      }
      else if ( ihave == 6 || ihave == 7 )
      {
        iterm = 1;
      }
      else if ( 1 < ihave )
      {
        ihave = 11;
      }
    }
/*
  Comma.
*/
    else if ( c == ',' || c == ';' )
    {
      if ( ihave != 1 )
      {
        iterm = 1;
        ihave = 12;
        *lchar = *lchar + 1;
      }
    }
/*
  Minus sign.
*/
    else if ( c == '-' )
    {
      if ( ihave == 1 )
      {
        ihave = 2;
        isgn = -1;
      }
      else if ( ihave == 6 )
      {
        ihave = 7;
        jsgn = -1;
      }
      else
      {
        iterm = 1;
      }
    }
/*
  Plus sign.
*/
    else if ( c == '+' )
    {
      if ( ihave == 1 )
      {
        ihave = 2;
      }
      else if ( ihave == 6 )
      {
        ihave = 7;
      }
      else
      {
        iterm = 1;
      }
    }
/*
  Decimal point.
*/
    else if ( c == '.' )
    {
      if ( ihave < 4 )
      {
        ihave = 4;
      }
      else if ( 6 <= ihave && ihave <= 8 )
      {
        ihave = 9;
      }
      else
      {
        iterm = 1;
      }
    }
/*
  Exponent marker.
*/
    else if ( ch_eqi ( c, 'E' ) || ch_eqi ( c, 'D' ) )
    {
      if ( ihave < 6 )
      {
        ihave = 6;
      }
      else
      {
        iterm = 1;
      }
    }
/*
  Digit.
*/
    else if ( ihave < 11 && '0' <= c && c <= '9' )
    {
      if ( ihave <= 2 )
      {
        ihave = 3;
      }
      else if ( ihave == 4 )
      {
        ihave = 5;
      }
      else if ( ihave == 6 || ihave == 7 )
      {
        ihave = 8;
      }
      else if ( ihave == 9 )
      {
        ihave = 10;
      }

      ndig = ch_to_digit ( c );

      if ( ihave == 3 )
      {
        rtop = 10.0 * rtop + ( double ) ndig;
      }
      else if ( ihave == 5 )
      {
        rtop = 10.0 * rtop + ( double ) ndig;
        rbot = 10.0 * rbot;
      }
      else if ( ihave == 8 )
      {
        jtop = 10 * jtop + ndig;
      }
      else if ( ihave == 10 )
      {
        jtop = 10 * jtop + ndig;
        jbot = 10 * jbot;
      }
    }
/*
  Anything else is regarded as a terminator.
*/
    else
    {
      iterm = 1;
    }
/*
  If we haven't seen a terminator, and we haven't examined the
  entire string, go get the next character.
*/
    if ( iterm == 1 || nchar <= *lchar + 1 )
    {
      break;
    }

  }
/*
  If we haven't seen a terminator, and we have examined the
  entire string, then we're done, and LCHAR is equal to NCHAR.
*/
  if ( iterm != 1 && (*lchar) + 1 == nchar )
  {
    *lchar = nchar;
  }
/*
  Number seems to have terminated.  Have we got a legal number?
  Not if we terminated in states 1, 2, 6 or 7!
*/
  if ( ihave == 1 || ihave == 2 || ihave == 6 || ihave == 7 )
  {
    *error = 1;
    return r;
  }
/*
  Number seems OK.  Form it.

  We have had some trouble with input of the form 1.0E-312.
  For now, let's assume anything less than 1.0E-20 is zero.
*/
  if ( jtop == 0 )
  {
    rexp = 1.0;
  }
  else
  {
    if ( jbot == 1 )
    {
      if ( jsgn * jtop < -20 )
      {
        rexp = 0.0;
      }
      else
      {
        rexp = pow ( ( double ) 10.0, ( double ) ( jsgn * jtop ) );
      }
    }
    else
    {
      if ( jsgn * jtop < -20 * jbot )
      {
        rexp = 0.0;
      }
      else
      {
        rexp = jsgn * jtop;
        rexp = rexp / jbot;
        rexp = pow ( ( double ) 10.0, ( double ) rexp );
      }
    }

  }

  r = isgn * rexp * rtop / rbot;

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

void timestamp ( )

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

    TIMESTAMP prints the current YMDHMS date as a time stamp.

  Example:

    31 May 2001 09:45:54 AM

  Licensing:

    This code is distributed under the MIT license.

  Modified:

    24 September 2003

  Author:

    John Burkardt

  Parameters:

    None
*/
{
# 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
}