st_io.cpp

# include <cstdlib>
# include <iostream>
# include <fstream>
# include <iomanip>
# include <cmath>
# include <ctime>
# include <cstring>

using namespace std;

# include "st_io.hpp"

//****************************************************************************80

int i4_max ( int i1, int i2 )

//****************************************************************************80
//
//  Purpose:
//
//    I4_MAX returns the maximum of two I4's.
//
//  Licensing:
//
//    This code is distributed under the GNU LGPL license.
//
//  Modified:
//
//    13 October 1998
//
//  Author:
//
//    John Burkardt
//
//  Parameters:
//
//    Input, int I1, I2, are two integers to be compared.
//
//    Output, int I4_MAX, the larger of I1 and I2.
//
{
  int value;

  if ( i2 < i1 )
  {
    value = i1;
  }
  else
  {
    value = i2;
  }
  return value;
}
//****************************************************************************80

int i4_min ( int i1, int i2 )

//****************************************************************************80
//
//  Purpose:
//
//    I4_MIN returns the minimum of two I4's.
//
//  Licensing:
//
//    This code is distributed under the GNU LGPL license.
//
//  Modified:
//
//    13 October 1998
//
//  Author:
//
//    John Burkardt
//
//  Parameters:
//
//    Input, int I1, I2, two integers to be compared.
//
//    Output, int I4_MIN, the smaller of I1 and I2.
//
{
  int value;

  if ( i1 < i2 )
  {
    value = i1;
  }
  else
  {
    value = i2;
  }
  return value;
}
//****************************************************************************80

void i4vec_dec ( int n, int a[] )

//****************************************************************************80
//
//  Purpose:
//
//    I4VEC_DEC decrements an I4VEC.
//
//  Discussion:
//
//    An I4VEC is a vector of I4's.
//
//  Licensing:
//
//    This code is distributed under the GNU LGPL license.
//
//  Modified:
//
//    15 July 2014
//
//  Author:
//
//    John Burkardt
//
//  Parameters:
//
//    Input, int N, the number of entries in the vectors.
//
//    Input/output, int A[N], the vector to be decremented.
//
{
  int i;

  for ( i = 0; i < n; i++ )
  {
    a[i] = a[i] - 1;
  }
  return;
}
//****************************************************************************80

void i4vec_inc ( int n, int a[] )

//****************************************************************************80
//
//  Purpose:
//
//    I4VEC_INC increments an I4VEC.
//
//  Discussion:
//
//    An I4VEC is a vector of I4's.
//
//  Licensing:
//
//    This code is distributed under the GNU LGPL license.
//
//  Modified:
//
//    15 July 2014
//
//  Author:
//
//    John Burkardt
//
//  Parameters:
//
//    Input, int N, the number of entries in the vectors.
//
//    Input/output, int A[N], the vector to be incremented.
//
{
  int i;

  for ( i = 0; i < n; i++ )
  {
    a[i] = a[i] + 1;
  }
  return;
}
//****************************************************************************80

int i4vec_max ( int n, int a[] )

//****************************************************************************80
//
//  Purpose:
//
//    I4VEC_MAX returns the value of the maximum element in an I4VEC.
//
//  Discussion:
//
//    An I4VEC is a vector of I4's.
//
//  Licensing:
//
//    This code is distributed under the GNU LGPL license.
//
//  Modified:
//
//    17 May 2003
//
//  Author:
//
//    John Burkardt
//
//  Parameters:
//
//    Input, int N, the number of entries in the array.
//
//    Input, int A[N], the array to be checked.
//
//    Output, int I4VEC_MAX, the value of the maximum element.  This
//    is set to 0 if N <= 0.
//
{
  int i;
  int value;

  if ( n <= 0 )
  {
    return 0;
  }

  value = a[0];

  for ( i = 1; i < n; i++ )
  {
    if ( value < a[i] )
    {
      value = a[i];
    }
  }

  return value;
}
//****************************************************************************80

int i4vec_min ( int n, int a[] )

//****************************************************************************80
//
//  Purpose:
//
//    I4VEC_MIN returns the value of the minimum element in an I4VEC.
//
//  Discussion:
//
//    An I4VEC is a vector of I4's.
//
//  Licensing:
//
//    This code is distributed under the GNU LGPL license.
//
//  Modified:
//
//    17 May 2003
//
//  Author:
//
//    John Burkardt
//
//  Parameters:
//
//    Input, int N, the number of entries in the array.
//
//    Input, int A[N], the array to be checked.
//
//    Output, int I4VEC_MIN, the value of the minimum element.  This
//    is set to 0 if N <= 0.
//
{
  int i;
  int value;

  if ( n <= 0 )
  {
    return 0;
  }

  value = a[0];

  for ( i = 1; i < n; i++ )
  {
    if ( a[i] < value )
    {
      value = a[i];
    }
  }
  return value;
}
//****************************************************************************80

void sort_heap_external ( int n, int &indx, int &i, int &j, int isgn )

//****************************************************************************80
//
//  Purpose:
//
//    SORT_HEAP_EXTERNAL externally sorts a list of items into ascending order.
//
//  Discussion:
//
//    The actual list is not passed to the routine.  Hence it may
//    consist of integers, reals, numbers, names, etc.  The user,
//    after each return from the routine, will be asked to compare or
//    interchange two items.
//
//    The current version of this code mimics the FORTRAN version,
//    so the values of I and J, in particular, are FORTRAN indices.
//
//  Licensing:
//
//    This code is distributed under the GNU LGPL license.
//
//  Modified:
//
//    06 January 2013
//
//  Author:
//
//    Original FORTRAN77 version by Albert Nijenhuis, Herbert Wilf.
//    C++ version by John Burkardt
//
//  Reference:
//
//    Albert Nijenhuis, Herbert Wilf,
//    Combinatorial Algorithms,
//    Academic Press, 1978, second edition,
//    ISBN 0-12-519260-6.
//
//  Parameters:
//
//    Input, int N, the length of the input list.
//
//    Input/output, int &INDX.
//    The user must set INDX to 0 before the first call.
//    On return,
//      if INDX is greater than 0, the user must interchange
//      items I and J and recall the routine.
//      If INDX is less than 0, the user is to compare items I
//      and J and return in ISGN a negative value if I is to
//      precede J, and a positive value otherwise.
//      If INDX is 0, the sorting is done.
//
//    Output, int &I, &J.  On return with INDX positive,
//    elements I and J of the user's list should be
//    interchanged.  On return with INDX negative, elements I
//    and J are to be compared by the user.
//
//    Input, int ISGN. On return with INDX negative, the
//    user should compare elements I and J of the list.  If
//    item I is to precede item J, set ISGN negative,
//    otherwise set ISGN positive.
//
{
  static int i_save = 0;
  static int j_save = 0;
  static int k = 0;
  static int k1 = 0;
  static int n1 = 0;
//
//  INDX = 0: This is the first call.
//
  if ( indx == 0 )
  {

    i_save = 0;
    j_save = 0;
    k = n / 2;
    k1 = k;
    n1 = n;
  }
//
//  INDX < 0: The user is returning the results of a comparison.
//
  else if ( indx < 0 )
  {
    if ( indx == -2 )
    {
      if ( isgn < 0 )
      {
        i_save = i_save + 1;
      }
      j_save = k1;
      k1 = i_save;
      indx = -1;
      i = i_save;
      j = j_save;
      return;
    }

    if ( 0 < isgn )
    {
      indx = 2;
      i = i_save;
      j = j_save;
      return;
    }

    if ( k <= 1 )
    {
      if ( n1 == 1 )
      {
        i_save = 0;
        j_save = 0;
        indx = 0;
      }
      else
      {
        i_save = n1;
        j_save = 1;
        n1 = n1 - 1;
        indx = 1;
      }
      i = i_save;
      j = j_save;
      return;
    }
    k = k - 1;
    k1 = k;
  }
//
//  0 < INDX: the user was asked to make an interchange.
//
  else if ( indx == 1 )
  {
    k1 = k;
  }

  for ( ; ; )
  {

    i_save = 2 * k1;

    if ( i_save == n1 )
    {
      j_save = k1;
      k1 = i_save;
      indx = -1;
      i = i_save;
      j = j_save;
      return;
    }
    else if ( i_save <= n1 )
    {
      j_save = i_save + 1;
      indx = -2;
      i = i_save;
      j = j_save;
      return;
    }

    if ( k <= 1 )
    {
      break;
    }

    k = k - 1;
    k1 = k;
  }

  if ( n1 == 1 )
  {
    i_save = 0;
    j_save = 0;
    indx = 0;
    i = i_save;
    j = j_save;
  }
  else
  {
    i_save = n1;
    j_save = 1;
    n1 = n1 - 1;
    indx = 1;
    i = i_save;
    j = j_save;
  }

  return;
}
//****************************************************************************80

void st_data_read ( string input_filename, int m, int n, int nst, 
  int ist[], int jst[], double ast[] )

//****************************************************************************80
//
//  Purpose:
//
//    ST_DATA_READ reads the data of an ST file.
//
//  Licensing:
//
//    This code is distributed under the GNU LGPL license.
//
//  Modified:
//
//    25 January 2014
//
//  Author:
//
//    John Burkardt
//
//  Parameters:
//
//    Input, string INPUT_FILENAME, the name of the ST file.
//
//    Input, int M, the number of rows.
//
//    Input, int N, the number of columns .
//
//    Input, int NST, the number of nonzeros .
//
//    Output, int IST[NST], JST[NST], the row and column indices.
//
//    Output, double AST[NST], the nonzero values.
//
{
  double aij;
  int i;
  ifstream input;
  int j;
  int k;
  int num;

  input.open ( input_filename.c_str ( ) );

  for ( k = 0; k < nst; k++ )
  {
    input >> i >> j >> aij;

    if ( !input )
    {
      cerr << "\n";
      cerr <<"ST_DATA_READ - Fatal error!\n";
      cerr << "  I/O error reading data index " << k << "\n";
      exit ( 1 );
    }

    ist[k] = i;
    jst[k] = j;
    ast[k] = aij;
  }

  input.close ( );

  return;
}
//****************************************************************************80

void st_header_print ( int i_min, int i_max, int j_min, int j_max, int m, 
  int n, int nst )

//****************************************************************************80
//
//  Purpose:
//
//    ST_HEADER_PRINT prints the header of an ST file.
//
//  Licensing:
//
//    This code is distributed under the GNU LGPL license.
//
//  Modified:
//
//    25 January 2014
//
//  Author:
//
//    John Burkardt
//
//  Parameters:
//
//    Input, int I_MIN, I_MAX, the minimum and maximum row indices.
//
//    Input, int J_MIN, J_MAX, the minimum and maximum column indices.
//
//    Input, int M, the number of rows.
//
//    Input, int N, the number of columns.
//
//    Input, int NST, the number of nonzeros.
//
{
  cout << "\n";
  cout << "  ST header information:\n";
  cout << "\n";
  cout << "  Minimum row index I_MIN = " << i_min << "\n";
  cout << "  Maximum row index I_MAX = " << i_max << "\n";
  cout << "  Minimum col index J_MIN = " << j_min << "\n";
  cout << "  Maximum col index J_MAX = " << j_max << "\n";
  cout << "  Number of rows        M = " << m << "\n";
  cout << "  Number of columns     N = " << n << "\n";
  cout << "  Number of nonzeros  NST = " << nst << "\n";

  return;
}
//****************************************************************************80

void st_header_read ( string input_filename, int &i_min, int &i_max, int &j_min, 
  int &j_max, int &m, int &n, int &nst )

//****************************************************************************80
//
//  Purpose:
//
//    ST_HEADER_READ reads the header of an ST file.
//
//  Licensing:
//
//    This code is distributed under the GNU LGPL license.
//
//  Modified:
//
//    25 January 2014
//
//  Author:
//
//    John Burkardt
//
//  Parameters:
//
//    Input, string INPUT_FILENAME, the name of the ST file.
//
//    Output, int &I_MIN, &I_MAX, the minimum and maximum row indices.
//
//    Output, int &J_MIN, &J_MAX, the minimum and maximum column indices.
//
//    Output, int &M, the number of rows.
//
//    Output, int &N, the number of columns .
//
//    Output, int &NST, the number of nonzeros.
//
{
  double aij;
  int i;
  const int i4_huge = 2147483647;
  ifstream input;
  int j;
  int num;

  input.open ( input_filename.c_str ( ) );

  nst = 0;
  i_min = + i4_huge;
  i_max = - i4_huge;
  j_min = + i4_huge;
  j_max = - i4_huge;

  for ( ; ; )
  {
    input >> i >> j >> aij;

    if ( ! input )
    {
      break;
    }

    nst = nst + 1;
    i_min = i4_min ( i_min, i );
    i_max = i4_max ( i_max, i );
    j_min = i4_min ( j_min, j );
    j_max = i4_max ( j_max, j );
  }

  input.close ( );

  m = i_max - i_min + 1;
  n = j_max - j_min + 1;

  return;
}
//****************************************************************************80

void st_print ( int m, int n, int nst, int ist[], int jst[], double ast[], 
  string title )

//****************************************************************************80
//
//  Purpose:
//
//    ST_PRINT prints a sparse matrix in ST format.
//
//  Licensing:
//
//    This code is distributed under the GNU LGPL license.
//
//  Modified:
//
//    15 July 2014
//
//  Author:
//
//    John Burkardt
//
//  Parameters:
//
//    Input, int M, the number of rows.
//
//    Input, int N, the number of columns.
//
//    Input, int NST, the number of ST elements.
//
//    Input, int IST[NST], JST[NST], the ST rows and columns.
//
//    Input, double AST[NST], the ST values.
//
//    Input, string TITLE, a title.
//
{
  int k;

  cout << "\n";
  cout << title << "\n";
  cout << "     #     I     J       A\n";
  cout << "  ----  ----  ----  --------------\n";
  cout << "\n";
  for ( k = 0; k < nst; k++ )
  {
    cout << setw(4) << k << "  "
         << setw(4) << ist[k] << "  "
         << setw(4) << jst[k] << "  "
         << setw(16) << ast[k] << "\n";
  }

  return;
}
//****************************************************************************80

void st_print_some ( int i_min, int i_max, int j_min, int j_max, int nst, 
  int  ist[], int jst[], double ast[], string title )

//****************************************************************************80
//
//  Purpose:
//
//    ST_PRINT_SOME prints some of a sparse matrix in ST format.
//
//  Licensing:
//
//    This code is distributed under the GNU LGPL license.
//
//  Modified:
//
//    15 July 2014
//
//  Author:
//
//    John Burkardt
//
//  Parameters:
//
//    Input, int I_MIN, IMAX, the first and last rows to print.
//
//    Input, int J_MIN, J_MAX, the first and last columns 
//    to print.
//
//    Input, int NST, the number of ST elements.
//
//    Input, int IST[NST], JST[NST], the ST rows and columns.
//
//    Input, double AST[NST], the ST values.
//
//    Input, string TITLE, a title.
//
{
  int k;

  cout << "\n";
  cout << title << "\n";
  cout << "     #     I     J       A\n";
  cout << "  ----  ----  ----  --------------\n";
  cout << "\n";
  for ( k = 0; k < nst; k++ )
  {
    if ( i_min <= ist[k] && ist[k] <= i_max &&
         j_min <= jst[k] && jst[k] <= j_max )
    {
      cout << setw(4) << k << "  "
           << setw(4) << ist[k] << "  "
           << setw(4) << jst[k] << "  "
           << setw(16) << ast[k] << "\n";
    }
  }

  return;
}
//****************************************************************************80

void st_sort_a ( int m, int n, int nst, int ist[], int jst[], double ast[] )

//****************************************************************************80
//
//  Purpose:
//
//    ST_SORT_A sorts the entries of an ST matrix by column.
//
//  Licensing:
//
//    This code is distributed under the GNU LGPL license.
//
//  Modified:
//
//    25 January 2014
//
//  Author:
//
//    John Burkardt
//
//  Parameters:
//
//    Input, int M, the number of rows.
//
//    Input, int N, the number of columns.
//
//    Input, int NST, the number of nonzeros.
//
//    Input/output, int IST[NST], JST[NST], the row and column indices.
//
//    Input/output, double AST[NST], the nonzero values.
//
{
  double aij;
  int cij;
  int i;
  int indx;
  int isgn;
  int j;
  int rij;
//
//  Initialize.
//
  i = 0;
  indx = 0;
  isgn = 0;
  j = 0;
//
//  Call the external heap sorter.
//
  for ( ; ; )
  {
    sort_heap_external ( nst, indx, i, j, isgn );
//
//  Interchange the I and J objects.
//
    if ( 0 < indx )
    {
      rij      = ist[i-1];
      ist[i-1] = ist[j-1];
      ist[j-1] = rij;

      cij      = jst[i-1];
      jst[i-1] = jst[j-1];
      jst[j-1] = cij;

      aij      = ast[i-1];
      ast[i-1] = ast[j-1];
      ast[j-1] = aij;
    }
//
//  Compare the I and J objects.
//
    else if ( indx < 0 )
    {
      if ( jst[i-1] == jst[j-1] )
      {
        if ( ist[i-1] < ist[j-1] )
        {
          isgn = - 1;
        }
        else if ( ist[i-1] == ist[j-1] )
        {
          isgn = 0;
        }
        else if ( ist[j-1] < ist[i-1] )
        {
          isgn = + 1;
        }
      }
      else if ( jst[i-1] < jst[j-1] )
      {
        isgn = - 1;
      }
      else if ( jst[j-1] < jst[i-1] )
      {
        isgn = + 1;
      }
    }
    else if ( indx == 0 )
    {
      break;
    }
  }
  return;
}
//****************************************************************************80

void st_transpose ( int &m, int &n, int nst, int ist[], int jst[], 
  double ast[] )

//****************************************************************************80
//
//  Purpose:
//
//    ST_TRANSPOSE transposes an ST matrix.
//
//  Licensing:
//
//    This code is distributed under the GNU LGPL license.
//
//  Modified:
//
//    20 July 2014
//
//  Author:
//
//    John Burkardt
//
//  Parameters:
//
//    Input/output, int &M, the number of rows.
//
//    Input/output, int &N, the number of columns.
//
//    Input, int NST, the number of nonzeros.
//
//    Input/output, int IST[NST], JST[NST], the row and column indices.
//
//    Input, double AST[NST], the nonzero values.
//
{
  int k;
  int t;

  t    = m;
  m = n;
  n = t;

  for ( k = 0; k < nst; k++ )
  {
    t      = ist[k];
    ist[k] = jst[k];
    jst[k] = t;
  }

  return;
}
//****************************************************************************80

void st_write ( string output_filename, int m, int n, int nst, int ist[], 
  int jst[], double ast[] )

//****************************************************************************80
//
//  Purpose:
//
//    ST_WRITE writes an ST file.
//
//  Licensing:
//
//    This code is distributed under the GNU LGPL license.
//
//  Modified:
//
//    25 January 2014
//
//  Author:
//
//    John Burkardt
//
//  Parameters:
//
//    Input, string OUTPUT_FILENAME, the name of the ST file.
//
//    Input, int M, the number of rows.
//
//    Input, int N, the number of columns.
//
//    Input, int NST, the number of nonzeros.
//
//    Input, int IST[NST], JST[NST], the row and column indices.
//
//    Input, double AST[NST], the nonzero values.
//
{
  ofstream output;
  int k;

  output.open ( output_filename.c_str ( ) );

  for ( k = 0; k < nst; k++ )
  {
    output << "  " << ist[k]
           << "  " << jst[k]
           << "  " << ast[k] << "\n";
  }

  output.close ( );

  return;
}
//****************************************************************************80

void timestamp ( )

//****************************************************************************80
//
//  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 GNU LGPL license.
//
//  Modified:
//
//    08 July 2009
//
//  Author:
//
//    John Burkardt
//
//  Parameters:
//
//    None
//
{
# define TIME_SIZE 40

  static char time_buffer[TIME_SIZE];
  const struct std::tm *tm_ptr;
  size_t len;
  std::time_t now;

  now = std::time ( NULL );
  tm_ptr = std::localtime ( &now );

  len = std::strftime ( time_buffer, TIME_SIZE, "%d %B %Y %I:%M:%S %p", tm_ptr );

  std::cout << time_buffer << "\n";

  return;
# undef TIME_SIZE
}