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

# include "latin_random.h"

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

int get_seed ( )

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

    GET_SEED returns a random seed for the random number generator.

  Licensing:

    This code is distributed under the MIT license. 

  Modified:

    17 November 2004

  Author:

    John Burkardt

  Parameters:

    Output, int GET_SEED, a random seed value.
*/
{
  time_t clock;
  int i4_huge = 2147483647;
  int ihour;
  int imin;
  int isec;
  int seed;
  struct tm *lt;
  time_t tloc;
/*
  If the internal seed is 0, generate a value based on the time.
*/
  clock = time ( &tloc );
  lt = localtime ( &clock );
/*
  Hours is 1, 2, ..., 12.
*/
  ihour = lt->tm_hour;

  if ( 12 < ihour )
  {
    ihour = ihour - 12;
  }
/*
  Move Hours to 0, 1, ..., 11
*/
  ihour = ihour - 1;

  imin = lt->tm_min;

  isec = lt->tm_sec;

  seed = isec + 60 * ( imin + 60 * ihour );
/*
  We want values in [1,43200], not [0,43199].
*/
  seed = seed + 1;
/*
  Remap SEED from [1,43200] to [1,HUGE].
*/
  seed = ( int ) 
    ( ( ( double ) seed )
    * ( ( double ) i4_huge ) / ( 60.0 * 60.0 * 12.0 ) );
/*
  Never use a seed of 0.
*/
  if ( seed == 0 )
  {
    seed = 1;
  }

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

int i4_uniform_ab ( int a, int b, int *seed )

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

    I4_UNIFORM_AB returns a scaled pseudorandom I4 between A and B.

  Discussion:

    The pseudorandom number should be uniformly distributed
    between A and B.

  Licensing:

    This code is distributed under the MIT license. 

  Modified:

    24 May 2012

  Author:

    John Burkardt

  Reference:

    Paul Bratley, Bennett Fox, Linus Schrage,
    A Guide to Simulation,
    Second Edition,
    Springer, 1987,
    ISBN: 0387964673,
    LC: QA76.9.C65.B73.

    Bennett Fox,
    Algorithm 647:
    Implementation and Relative Efficiency of Quasirandom
    Sequence Generators,
    ACM Transactions on Mathematical Software,
    Volume 12, Number 4, December 1986, pages 362-376.

    Pierre L'Ecuyer,
    Random Number Generation,
    in Handbook of Simulation,
    edited by Jerry Banks,
    Wiley, 1998,
    ISBN: 0471134031,
    LC: T57.62.H37.

    Peter Lewis, Allen Goodman, James Miller,
    A Pseudo-Random Number Generator for the System/360,
    IBM Systems Journal,
    Volume 8, Number 2, 1969, pages 136-143.

  Parameters:

    Input, int A, B, the limits of the interval.

    Input/output, int *SEED, the "seed" value, which should NOT be 0.
    On output, SEED has been updated.

    Output, int I4_UNIFORM_AB, a number between A and B.
*/
{
  int c;
  const int i4_huge = 2147483647;
  int k;
  float r;
  int value;

  if ( *seed == 0 )
  {
    fprintf ( stderr, "\n" );
    fprintf ( stderr, "I4_UNIFORM_AB - Fatal error!\n" );
    fprintf ( stderr, "  Input value of SEED = 0.\n" );
    exit ( 1 );
  }
/*
  Guaranteee A <= B.
*/
  if ( b < a )
  {
    c = a;
    a = b;
    b = c;
  }

  k = *seed / 127773;

  *seed = 16807 * ( *seed - k * 127773 ) - k * 2836;

  if ( *seed < 0 )
  {
    *seed = *seed + i4_huge;
  }

  r = ( float ) ( *seed ) * 4.656612875E-10;
/*
  Scale R to lie between A-0.5 and B+0.5.
*/
  r = ( 1.0 - r ) * ( ( float ) ( a ) - 0.5 ) 
    +         r   * ( ( float ) ( b ) + 0.5 );
/*
  Round R to the nearest integer.
*/
  value = round ( r );
/*
  Guarantee that A <= VALUE <= B.
*/
  if ( value < a )
  {
    value = a;
  }
  if ( b < value )
  {
    value = b;
  }

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

void i4vec_print ( int n, int a[], char *title )

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

    I4VEC_PRINT prints an I4VEC.

  Discussion:

    An I4VEC is a vector of I4's.

  Licensing:

    This code is distributed under the MIT license.

  Modified:

    14 November 2003

  Author:

    John Burkardt

  Parameters:

    Input, int N, the number of components of the vector.

    Input, int A[N], the vector to be printed.

    Input, char *TITLE, a title.
*/
{
  int i;

  fprintf ( stdout, "\n" );
  fprintf ( stdout, "%s\n", title );
  fprintf ( stdout, "\n" );

  for ( i = 0; i < n; i++ )
  {
    fprintf ( stdout, "  %6d: %8d\n", i, a[i] );
  }
  return;
}
/******************************************************************************/

double *latin_random_new ( int dim_num, int point_num, int *seed )

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

    LATIN_RANDOM_NEW returns points in a Latin Random square.

  Discussion:

    In each spatial dimension, there will be exactly one
    point whose coordinate value lies between consecutive
    values in the list:

      ( 0, 1, 2, ..., point_num ) / point_num

  Licensing:

    This code is distributed under the MIT license. 

  Modified:

    08 April 2003

  Author:

    John Burkardt

  Parameters:

    Input, int DIM_NUM, the spatial dimension.

    Input, int POINT_NUM, the number of points.

    Input/output, int *SEED, a seed for UNIFORM.

    Output, double LATIN_RANDOM_NEW[DIM_NUM,POINT_NUM], the points.
*/
{
  int i;
  int j;
  int *perm;
  double *x;

  x = r8mat_uniform_01_new ( dim_num, point_num, seed );
/*
  For spatial dimension I, 
    pick a random permutation of 1 to POINT_NUM,
    force the corresponding I-th components of X to lie in the
    interval ( PERM[J]-1, PERM[J] ) / POINT_NUM.
*/
  for ( i = 0; i < dim_num; i++ )
  {
    perm = perm_uniform_new ( point_num, seed );

    for ( j = 0; j < point_num; j++ )
    {
      x[i+j*dim_num] = ( ( ( double ) perm[j] ) + x[i+j*dim_num] ) 
                       / ( ( double ) point_num );
    }
    free ( perm );
  }
  return x;
}
/******************************************************************************/

int *perm_uniform_new ( int n, int *seed )

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

    PERM_UNIFORM_NEW selects a random permutation of N objects.

  Licensing:

    This code is distributed under the MIT license.

  Modified:

    25 February 2014

  Author:

    John Burkardt

  Reference:

    Albert Nijenhuis, Herbert Wilf,
    Combinatorial Algorithms,
    Academic Press, 1978, second edition,
    ISBN 0-12-519260-6.

  Parameters:

    Input, int N, the number of objects to be permuted.

    Input/output, int *SEED, a seed for the random number generator.

    Output, int PERM_UNIFORM_NEW[N], a permutation of
    (BASE, BASE+1, ..., BASE+N-1).
*/
{
  int i;
  int j;
  int k;
  int *p;

  p = ( int * ) malloc ( n * sizeof ( int ) );

  for ( i = 0; i < n; i++ )
  {
    p[i] = i;
  }

  for ( i = 0; i < n - 1; i++ )
  {
    j = i4_uniform_ab ( i, n - 1, seed );
    k    = p[i];
    p[i] = p[j];
    p[j] = k;
  }

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

void r8mat_transpose_print ( int m, int n, double a[], char *title )

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

    R8MAT_TRANSPOSE_PRINT prints an R8MAT, transposed.

  Discussion:

    An R8MAT is a doubly dimensioned array of R8 values, stored as a vector
    in column-major order.

  Licensing:

    This code is distributed under the MIT license.

  Modified:

    28 May 2008

  Author:

    John Burkardt

  Parameters:

    Input, int M, N, the number of rows and columns.

    Input, double A[M*N], an M by N matrix to be printed.

    Input, char *TITLE, a title.
*/
{
  r8mat_transpose_print_some ( m, n, a, 1, 1, m, n, title );

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

void r8mat_transpose_print_some ( int m, int n, double a[], int ilo, int jlo,
  int ihi, int jhi, char *title )

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

    R8MAT_TRANSPOSE_PRINT_SOME prints some of an R8MAT, transposed.

  Discussion:

    An R8MAT is a doubly dimensioned array of R8 values, stored as a vector
    in column-major order.

  Licensing:

    This code is distributed under the MIT license.

  Modified:

    10 September 2013

  Author:

    John Burkardt

  Parameters:

    Input, int M, N, the number of rows and columns.

    Input, double A[M*N], an M by N matrix to be printed.

    Input, int ILO, JLO, the first row and column to print.

    Input, int IHI, JHI, the last row and column to print.

    Input, char *TITLE, a title.
*/
{
# define INCX 5

  int i;
  int i2;
  int i2hi;
  int i2lo;
  int i2lo_hi;
  int i2lo_lo;
  int inc;
  int j;
  int j2hi;
  int j2lo;

  fprintf ( stdout, "\n" );
  fprintf ( stdout, "%s\n", title );

  if ( m <= 0 || n <= 0 )
  {
    fprintf ( stdout, "\n" );
    fprintf ( stdout, "  (None)\n" );
    return;
  }

  if ( ilo < 1 )
  {
    i2lo_lo = 1;
  }
  else
  {
    i2lo_lo = ilo;
  }

  if ( ihi < m )
  {
    i2lo_hi = m;
  }
  else
  {
    i2lo_hi = ihi;
  }

  for ( i2lo = i2lo_lo; i2lo <= i2lo_hi; i2lo = i2lo + INCX )
  {
    i2hi = i2lo + INCX - 1;

    if ( m < i2hi )
    {
      i2hi = m;
    }
    if ( ihi < i2hi )
    {
      i2hi = ihi;
    }

    inc = i2hi + 1 - i2lo;

    fprintf ( stdout, "\n" );
    fprintf ( stdout, "  Row:" );
    for ( i = i2lo; i <= i2hi; i++ )
    {
      fprintf ( stdout, "  %7d     ", i - 1 );
    }
    fprintf ( stdout, "\n" );
    fprintf ( stdout, "  Col\n" );
    fprintf ( stdout, "\n" );

    if ( jlo < 1 )
    {
      j2lo = 1;
    }
    else
    {
      j2lo = jlo;
    }
    if ( n < jhi )
    {
      j2hi = n;
    }
    else
    {
      j2hi = jhi;
    }
    for ( j = j2lo; j <= j2hi; j++ )
    {
      fprintf ( stdout, "%5d:", j - 1 );
      for ( i2 = 1; i2 <= inc; i2++ )
      {
        i = i2lo - 1 + i2;
        fprintf ( stdout, "  %14g", a[(i-1)+(j-1)*m] );
      }
      fprintf ( stdout, "\n" );
    }
  }

  return;
# undef INCX
}
/******************************************************************************/

double *r8mat_uniform_01_new ( int m, int n, int *seed )

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

    R8MAT_UNIFORM_01_NEW fills an R8MAT with pseudorandom values scaled to [0,1].

  Discussion:

    An R8MAT is a doubly dimensioned array of R8 values, stored as a vector
    in column-major order.

    This routine implements the recursion

      seed = 16807 * seed mod ( 2^31 - 1 )
      unif = seed / ( 2^31 - 1 )

    The integer arithmetic never requires more than 32 bits,
    including a sign bit.

  Licensing:

    This code is distributed under the MIT license.

  Modified:

    30 June 2009

  Author:

    John Burkardt

  Reference:

    Paul Bratley, Bennett Fox, Linus Schrage,
    A Guide to Simulation,
    Springer Verlag, pages 201-202, 1983.

    Bennett Fox,
    Algorithm 647:
    Implementation and Relative Efficiency of Quasirandom
    Sequence Generators,
    ACM Transactions on Mathematical Software,
    Volume 12, Number 4, pages 362-376, 1986.

    Philip Lewis, Allen Goodman, James Miller,
    A Pseudo-Random Number Generator for the System/360,
    IBM Systems Journal,
    Volume 8, pages 136-143, 1969.

  Parameters:

    Input, int M, N, the number of rows and columns.

    Input/output, int *SEED, the "seed" value.  Normally, this
    value should not be 0, otherwise the output value of SEED
    will still be 0, and R8_UNIFORM will be 0.  On output, SEED has
    been updated.

    Output, double R8MAT_UNIFORM_01_NEW[M*N], a matrix of pseudorandom values.
*/
{
  int i;
  const int i4_huge = 2147483647;
  int j;
  int k;
  double *r;

  r = ( double * ) malloc ( m * n * sizeof ( double ) );

  for ( j = 0; j < n; j++ )
  {
    for ( i = 0; i < m; i++ )
    {
      k = *seed / 127773;

      *seed = 16807 * ( *seed - k * 127773 ) - k * 2836;

      if ( *seed < 0 )
      {
        *seed = *seed + i4_huge;
      }
      r[i+j*m] = ( double ) ( *seed ) * 4.656612875E-10;
    }
  }

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

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 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, "  %24.16g", table[i+j*m] );
*/
    }
    fprintf ( output, "\n" );
  }
/*
  Close the file.
*/
  fclose ( output );

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

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 );

  fprintf ( stdout, "%s\n", time_buffer );

  return;
# undef TIME_SIZE
}