# include # include # include # include # include # include # include using namespace std; # include "hammersley.hpp" // // These variables are accessible to the user via calls to routines. // static int *hammersley_BASE = NULL; static int *hammersley_LEAP = NULL; static int hammersley_DIM_NUM = -1; static int *hammersley_SEED = NULL; static int hammersley_STEP = -1; //****************************************************************************80 double arc_cosine ( double c ) //****************************************************************************80 // // Purpose: // // ARC_COSINE computes the arc cosine function, with argument truncation. // // Discussion: // // If you call your system ACOS routine with an input argument that is // outside the range [-1.0, 1.0 ], you may get an unpleasant surprise. // This routine truncates arguments outside the range. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 28 February 2003 // // Author: // // John Burkardt // // Parameters: // // Input, double C, the argument, which is usually between -1 and 1. // // Output, double ARC_COSINE, an angle whose cosine is C. // { double pi = 3.141592653589793; if ( c < -1.0 ) { return -pi; } else if ( 1.0 < c ) { return 0.0; } else { return acos ( c ); } } //****************************************************************************80 double atan4 ( double y, double x ) //****************************************************************************80 // // Purpose: // // ATAN4 computes the inverse tangent of the ratio Y / X. // // Discussion: // // ATAN4 returns an angle whose tangent is ( Y / X ), a job which // the built in functions ATAN and ATAN2 already do. // // However: // // * ATAN4 always returns a positive angle, between 0 and 2 PI, // while ATAN and ATAN2 return angles in the interval [-PI/2,+PI/2] // and [-PI,+PI] respectively; // // * ATAN4 accounts for the signs of X and Y, (as does ATAN2). The ATAN // function by contrast always returns an angle in the first or fourth // quadrants. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 18 April 1999 // // Author: // // John Burkardt // // Parameters: // // Input, double Y, X, two quantities which represent the tangent of // an angle. If Y is not zero, then the tangent is (Y/X). // // Output, double ATAN4, a positive angle whose tangent is (Y/X), and // which lies in the appropriate quadrant so that the signs of its // cosine and sine match those of X and Y. // { double abs_x; double abs_y; double pi = 3.141592653589793; double theta; double theta_0; // // Special cases: // if ( x == 0.0 ) { if ( 0.0 < y ) { theta = pi / 2.0; } else if ( y < 0.0 ) { theta = 3.0 * pi / 2.0; } else { theta = 0.0; } } else if ( y == 0.0 ) { if ( 0.0 < x ) { theta = 0.0; } else if ( x < 0.0 ) { theta = pi; } } // // We assume that ATAN2 is correct when both arguments are positive. // else { abs_y = fabs ( y ); abs_x = fabs ( x ); theta_0 = atan2 ( abs_y, abs_x ); if ( 0.0 < x && 0.0 < y ) { theta = theta_0; } else if ( x < 0.0 && 0.0 < y ) { theta = pi - theta_0; } else if ( x < 0.0 && y < 0.0 ) { theta = pi + theta_0; } else if ( 0.0 < x && y < 0.0 ) { theta = 2.0 * pi - theta_0; } } return theta; } //****************************************************************************80 char digit_to_ch ( int i ) //****************************************************************************80 // // Purpose: // // DIGIT_TO_CH returns the base 10 digit character corresponding to a digit. // // Example: // // I C // ----- --- // 0 '0' // 1 '1' // ... ... // 9 '9' // 10 '*' // -83 '*' // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 16 June 2003 // // Author: // // John Burkardt // // Parameters: // // Input, int I, the digit, which should be between 0 and 9. // // Output, char DIGIT_TO_CH, the appropriate character '0' through '9' or '*'. // { char c; if ( 0 <= i && i <= 9 ) { c = '0' + i; } else { c = '*'; } return c; } //****************************************************************************80 int get_seed ( ) //****************************************************************************80 // // Purpose: // // GET_SEED returns a random seed for the random number generator. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 15 September 2003 // // Author: // // John Burkardt // // Parameters: // // Output, int GET_SEED, a random seed value. // { # define I4_MAX 2147483647 time_t clock; int i; 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 ISEED from [1,43200] to [1,I4_MAX]. // seed = ( int ) ( ( ( double ) seed ) * ( ( double ) I4_MAX ) / ( 60.0 * 60.0 * 12.0 ) ); // // Never use a seed of 0. // if ( seed == 0 ) { seed = 1; } return seed; # undef I4_MAX } //****************************************************************************80 bool halham_leap_check ( int dim_num, int leap[] ) //****************************************************************************80 // // Purpose: // // HALHAM_LEAP_CHECK checks LEAP for a Halton or Hammersley sequence. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 16 September 2004 // // Author: // // John Burkardt // // Parameters: // // Input, int DIM_NUM, the spatial dimension. // // Input, int LEAP[DIM_NUM], the successive jumps in the sequence. // Each entry must be greater than 0. // // Output, bool HALHAM_LEAP_CHECK, is true if LEAP is legal. // { int i; bool value; value = true; for ( i = 0; i < dim_num; i++ ) { if ( leap[i] < 1 ) { cout << "\n"; cout << "HALHAM_LEAP_CHECK - Fatal error!\n"; cout << " Leap entries must be greater than 0.\n"; i4vec_transpose_print ( dim_num, leap, "LEAP: " ); value = false; break; } } return value; } //****************************************************************************80 bool halham_n_check ( int n ) //****************************************************************************80 // // Purpose: // // HALHAM_N_CHECK checks N for a Halton or Hammersley sequence. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 16 September 2004 // // Author: // // John Burkardt // // Parameters: // // Input, int N, the number of points in the subsequence. // // Output, bool HALHAM_N_CHECK, is true if N is legal. // { bool value; if ( n < 1 ) { cout << "\n"; cout << "HALHAM_N_CHECK - Fatal error!\n"; cout << " N < 0."; cout << " N = " << n << "\n"; value = false; } else { value = true; } return value; } //****************************************************************************80 bool halham_dim_num_check ( int dim_num ) //****************************************************************************80 // // Purpose: // // HALHAM_DIM_NUM_CHECK checks DIM_NUM for a Halton or Hammersley sequence. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 16 September 2004 // // Author: // // John Burkardt // // Parameters: // // Input, int DIM_NUM, the spatial dimension. // DIM_NUM must be positive. // // Output, bool HALHAM_DIM_NUM_CHECK, is true if DIM_NUM is legal. // { bool value; if ( dim_num < 1 ) { cout << "\n"; cout << "HALHAM_DIM_NUM_CHECK - Fatal error!\n"; cout << " DIM_NUM < 0."; cout << " DIM_NUM = " << dim_num << "\n"; value = false; } else { value = true; } return value; } //****************************************************************************80 bool halham_seed_check ( int dim_num, int seed[] ) //****************************************************************************80 // // Purpose: // // HALHAM_SEED_CHECK checks SEED for a Halton or Hammersley sequence. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 16 September 2004 // // Author: // // John Burkardt // // Parameters: // // Input, int DIM_NUM, the spatial dimension. // // Input, int SEED[DIM_NUM], the sequence index // corresponding to STEP = 0. Each entry must be 0 or greater. // // Output, bool HALHAM_SEED_CHECK, is true if SEED is legal. // { int i; bool value; value = true; for ( i = 0; i < dim_num; i++ ) { if ( seed[i] < 0 ) { cout << "\n"; cout << "HALHAM_SEED_CHECK - Fatal error!\n"; cout << " SEED entries must be nonnegative.\n"; i4vec_transpose_print ( dim_num, seed, "SEED: " ); value = false; break; } } return value; } //****************************************************************************80 bool halham_step_check ( int step ) //****************************************************************************80 // // Purpose: // // HALHAM_STEP_CHECK checks STEP for a Halton or Hammersley sequence. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 16 September 2004 // // Author: // // John Burkardt // // Parameters: // // Input, int STEP, the index of the subsequence element. // STEP must be 1 or greater. // // Output, bool HALHAM_STEP_CHECK, is true if STEP is legal. // { bool value; if ( step < 0 ) { cout << "\n"; cout << "HALHAM_STEP_CHECK - Fatal error!\n"; cout << " STEP < 0."; cout << " STEP = " << step << "\n"; value = false; } else { value = true; } return value; } //****************************************************************************80 void halham_write ( int dim_num, int n, int step, int seed[], int leap[], int base[], double r[], char *file_out_name ) //****************************************************************************80 // // Purpose: // // HALHAM_WRITE writes a Halton or Hammersley dataset to a file. // // Discussion: // // The initial lines of the file are comments, which begin with a // "#" character. // // Thereafter, each line of the file contains the DIM_NUM-dimensional // components of the next entry of the dataset. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 16 September 2004 // // Author: // // John Burkardt // // Parameters: // // Input, int DIM_NUM, the spatial dimension. // // Input, int N, the number of elements in the subsequence. // // Input, int STEP, the index of the subsequence element. // 0 <= STEP is required. // // Input, int SEED[DIM_NUM], the sequence index for STEP = 0. // // Input, int LEAP[DIM_NUM], the successive jumps in the sequence. // // Input, int BASE[DIM_NUM], the bases. // // Input, double R[DIM_NUM*N], the points. // // Input, char *FILE_OUT_NAME, the name of the output file. // { ofstream file_out; int i; int j; int mhi; int mlo; char *s; file_out.open ( file_out_name ); if ( !file_out ) { cout << "\n"; cout << "HALHAM_WRITE - Fatal error!\n"; cout << " Could not open the output file.\n"; exit ( 1 ); } s = timestring ( ); file_out << "# " << file_out_name << "\n"; file_out << "# created by routine HALHAM_WRITE.CC" << "\n"; file_out << "# at " << s << "\n"; file_out << "#\n"; file_out << "# DIM_NUM = " << setw(12) << dim_num << "\n"; file_out << "# N = " << setw(12) << n << "\n"; file_out << "# STEP = " << setw(12) << step << "\n"; for ( mlo = 1; mlo <= dim_num; mlo = mlo + 5 ) { mhi = i4_min ( mlo + 5 - 1, dim_num ); if ( mlo == 1 ) { file_out << "# SEED = "; } else { file_out << "# "; } for ( i = mlo; i <= mhi; i++ ) { file_out << setw(12) << seed[i-1]; } file_out << "\n"; } for ( mlo = 1; mlo <= dim_num; mlo = mlo + 5 ) { mhi = i4_min ( mlo + 5 - 1, dim_num ); if ( mlo == 1 ) { file_out << "# LEAP = "; } else { file_out << "# "; } for ( i = mlo; i <= mhi; i++ ) { file_out << setw(12) << leap[i-1]; } file_out << "\n"; } for ( mlo = 1; mlo <= dim_num; mlo = mlo + 5 ) { mhi = i4_min ( mlo + 5 - 1, dim_num ); if ( mlo == 1 ) { file_out << "# BASE = "; } else { file_out << "# "; } for ( i = mlo; i <= mhi; i++ ) { file_out << setw(12) << base[i-1]; } file_out << "\n"; } file_out << "# EPSILON (unit roundoff) = " << r8_epsilon ( ) << "\n"; file_out << "#\n"; for ( j = 0; j < n; j++ ) { for ( i = 0; i < dim_num; i++ ) { file_out << setw(10) << r[i+j*dim_num] << " "; } file_out << "\n"; } file_out.close ( ); delete [] s; return; } //****************************************************************************80 void hammersley ( double r[] ) //****************************************************************************80 // // Purpose: // // HAMMERSLEY computes the next element in a leaped Hammersley subsequence. // // Discussion: // // The DIM_NUM-dimensional Hammersley sequence is really DIM_NUM separate // sequences, each generated by a particular base. If the base is // greater than 1, a standard 1-dimensional // van der Corput sequence is generated. But if the base is // negative, this is a signal that the much simpler sequence J/(-BASE) // is to be generated. For the standard Hammersley sequence, the // first spatial coordinate uses a base of (-N), and subsequent // coordinates use bases of successive primes (2, 3, 5, 7, 11, ...). // This program allows the user to specify any combination of bases, // included nonprimes and repeated values. // // This routine selects elements of a "leaped" subsequence of the // Hammersley sequence. The subsequence elements are indexed by a // quantity called STEP, which starts at 0. The STEP-th subsequence // element is simply element // // SEED(1:DIM_NUM) + STEP * LEAP(1:DIM_NUM) // // of the original sequence. // // // This routine "hides" a number of input arguments. To specify these // arguments explicitly, use I4_TO_HAMMERSLEY instead. // // All the arguments have default values. However, if you want to // examine or change them, you may call the appropriate routine // before calling HAMMERSLEY. // // The arguments that the user may set include: // // * DIM_NUM, the spatial dimension, // Default: DIM_NUM = 1; // Required: 1 <= DIM_NUM is required. // // * STEP, the subsequence index. // Default: STEP = 0. // Required: 0 <= STEP. // // * SEED(1:DIM_NUM), the Hammersley sequence element corresponding to STEP = 0. // Default SEED = (0, 0, ... 0). // Required: 0 <= SEED(1:DIM_NUM). // // * LEAP(1:DIM_NUM), the succesive jumps in the Hammersley sequence. // Default: LEAP = (1, 1, ..., 1). // Required: 1 <= LEAP(1:DIM_NUM). // // * BASE(1:DIM_NUM), the bases. // Default: BASE = (2, 3, 5, 7, 11, ... ) or (-N, 2, 3, 5, 7, 11...) // if N is known. // Required: 1 < BASE(I) for a van der Corput dimension I, or // BASE(I) < 0 for a fraction sequence J/|BASE(I)|. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 16 July 2004 // // Author: // // John Burkardt // // Reference: // // J M Hammersley, // Monte Carlo methods for solving multivariable problems, // Proceedings of the New York Academy of Science, // Volume 86, 1960, pages 844-874. // // Ladislav Kocis and William Whiten, // Computational Investigations of Low-Discrepancy Sequences, // ACM Transactions on Mathematical Software, // Volume 23, Number 2, 1997, pages 266-294. // // Parameters: // // Output, double R[DIM_NUM], the next element of the leaped Hammersley // subsequence. // { int *base; int i; int dim_num; int *leap; int *seed; int step; if ( hammersley_DIM_NUM < 1 ) { hammersley_DIM_NUM = 1; } if ( hammersley_STEP < 0 ) { hammersley_STEP = 0; } if ( !hammersley_SEED ) { hammersley_SEED = new int[hammersley_DIM_NUM]; for ( i = 0; i < hammersley_DIM_NUM; i++ ) { hammersley_SEED[i] = 0; } } if ( !hammersley_LEAP ) { hammersley_LEAP = new int[hammersley_DIM_NUM]; for ( i = 0; i < hammersley_DIM_NUM; i++ ) { hammersley_LEAP[i] = 1; } } if ( !hammersley_BASE ) { hammersley_BASE = new int[hammersley_DIM_NUM]; for ( i = 0; i < hammersley_DIM_NUM; i++ ) { hammersley_BASE[i] = prime ( i + 1 ); } } dim_num = hammersley_DIM_NUM; step = hammersley_STEP; seed = hammersley_SEED; leap = hammersley_LEAP; base = hammersley_BASE; i4_to_hammersley ( dim_num, step, seed, leap, base, r ); hammersley_STEP = hammersley_STEP + 1; return; } //****************************************************************************80 bool hammersley_base_check ( int dim_num, int base[] ) //****************************************************************************80 // // Purpose: // // HAMMERSLEY_BASE_CHECK checks BASE for a Hammersley sequence. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 16 July 2004 // // Author: // // John Burkardt // // Parameters: // // Input, int DIM_NUM, the spatial dimension. // // Input, int BASE[DIM_NUM], the bases. // // Output, bool HAMMERSLEY_BASE_CHECK, is true if BASE is legal. // { int i; bool value; value = true; for ( i = 0; i < dim_num; i++ ) { if ( base[i] == 0 || base[i] == 1 ) { cout << "\n"; cout << "HAMMERSLEY_BASE_CHECK - Fatal error!\n"; cout << " Bases may not be 0 or 1.\n"; i4vec_transpose_print ( dim_num, base, "BASE: " ); value = false; break; } } return value; } //****************************************************************************80 int *hammersley_base_get ( ) //****************************************************************************80 // // Purpose: // // HAMMERSLEY_BASE_GET gets the base vector for a leaped Hammersley subsequence. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 28 February 2003 // // Author: // // John Burkardt // // Parameters: // // Output, int *HAMMERSLEY_BASE_GET, a pointer to the Hammersley bases. // { return hammersley_BASE; } //****************************************************************************80 void hammersley_base_set ( int base[] ) //****************************************************************************80 // // Purpose: // // HAMMERSLEY_BASE_SET sets the base vector for a leaped Hammersley subsequence. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 28 February 2003 // // Author: // // John Burkardt // // Parameters: // // Input, int BASE[DIM_NUM], the bases. // { int i; if ( !hammersley_base_check ( hammersley_DIM_NUM, base ) ) { exit ( 1 ); } for ( i = 0; i < hammersley_DIM_NUM; i++ ) { hammersley_BASE[i] = base[i]; } return; } //****************************************************************************80 int hammersley_dim_num_get ( ) //****************************************************************************80 // // Purpose: // // HAMMERSLEY_DIM_NUM_GET gets the spatial dimension for a leaped Hammersley subsequence. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 28 February 2003 // // Author: // // John Burkardt // // Parameters: // // Output, int HAMMERSLEY_DIM_NUM_GET, the spatial dimension. // { return hammersley_DIM_NUM; } //****************************************************************************80 void hammersley_dim_num_set ( int dim_num ) //****************************************************************************80 // // Purpose: // // HAMMERSLEY_DIM_NUM_SET sets the spatial dimension for a leaped Hammersley subsequence. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 28 February 2003 // // Author: // // John Burkardt // // Parameters: // // Input, int DIM_NUM, the spatial dimension. // DIM_NUM must be positive. // { int i; if ( !halham_dim_num_check ( dim_num ) ) { exit ( 1 ); } if ( hammersley_DIM_NUM != dim_num && 0 < hammersley_DIM_NUM ) { delete [] hammersley_BASE; delete [] hammersley_LEAP; delete [] hammersley_SEED; } if ( hammersley_DIM_NUM != dim_num ) { hammersley_DIM_NUM = dim_num; hammersley_SEED = new int[hammersley_DIM_NUM]; for ( i = 0; i < hammersley_DIM_NUM; i++ ) { hammersley_SEED[i] = 0; } hammersley_LEAP = new int[hammersley_DIM_NUM]; for ( i = 0; i < hammersley_DIM_NUM; i++ ) { hammersley_LEAP[i] = 1; } hammersley_BASE = new int[hammersley_DIM_NUM]; for ( i = 0; i < hammersley_DIM_NUM; i++ ) { hammersley_BASE[i] = prime ( i + 1 ); } hammersley_STEP = 0; } return; } //****************************************************************************80 int *hammersley_leap_get ( ) //****************************************************************************80 // // Purpose: // // HAMMERSLEY_LEAP_GET gets the leap vector for a leaped Hammersley subsequence. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 06 July 2004 // // Author: // // John Burkardt // // Parameters: // // Output, int *HAMMERSLEY_LEAP_GET, a pointer to the successive jumps in // the Hammersley sequence. // { return hammersley_LEAP; } //****************************************************************************80 void hammersley_leap_set ( int leap[] ) //****************************************************************************80 // // Purpose: // // HAMMERSLEY_LEAP_SET sets the leap vector for a leaped Hammersley subsequence. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 06 July 2004 // // Author: // // John Burkardt // // Parameters: // // Input, int LEAP[HAMMERSLEY_DIM_NUM], the successive jumps in the Hammersley sequence. // Each entry must be greater than 0. // { int i; if ( !halham_leap_check ( hammersley_DIM_NUM, leap ) ) { exit ( 1 ); } for ( i = 0; i < hammersley_DIM_NUM; i++ ) { hammersley_LEAP[i] = leap[i]; } return; } //****************************************************************************80 int *hammersley_seed_get ( ) //****************************************************************************80 // // Purpose: // // HAMMERSLEY_SEED_GET gets the seed vector for a leaped Hammersley subsequence. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 06 July 2004 // // Author: // // John Burkardt // // Parameters: // // Output, int *HAMMERSLEY_SEED_GET, a pointer to the Hammersley sequence index // corresponding to STEP = 0. // { return hammersley_SEED; } //****************************************************************************80 void hammersley_seed_set ( int seed[] ) //****************************************************************************80 // // Purpose: // // HAMMERSLEY_SEED_SET sets the seed vector for a leaped Hammersley subsequence. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 06 July 2004 // // Author: // // John Burkardt // // Parameters: // // Input, int SEED[HAMMERSLEY_DIM_NUM], the Hammersley sequence index // corresponding to STEP = 0. Each entry must be 0 or greater. // { int i; if ( !halham_seed_check ( hammersley_DIM_NUM, seed ) ) { exit ( 1 ); } for ( i = 0; i < hammersley_DIM_NUM; i++ ) { hammersley_SEED[i] = seed[i]; } return; } //****************************************************************************80 void hammersley_sequence ( int n, double r[] ) //****************************************************************************80 // // Purpose: // // HAMMERSLEY_SEQUENCE computes N elements in an DIM_NUM-dimensional Hammersley sequence. // // Discussion: // // The DIM_NUM-dimensional Hammersley sequence is really DIM_NUM separate // sequences, each generated by a particular base. If the base is // greater than 1, a standard 1-dimensional // van der Corput sequence is generated. But if the base is // negative, this is a signal that the much simpler sequence J/(-BASE) // is to be generated. For the standard Hammersley sequence, the // first spatial coordinate uses a base of (-N), and subsequent // coordinates use bases of successive primes (2, 3, 5, 7, 11, ...). // This program allows the user to specify any combination of bases, // included nonprimes and repeated values. // // This routine selects elements of a "leaped" subsequence of the // Hammersley sequence. The subsequence elements are indexed by a // quantity called STEP, which starts at 0. The STEP-th subsequence // element is simply element // // SEED(1:DIM_NUM) + STEP * LEAP(1:DIM_NUM) // // of the original Hammersley sequence. // // // This routine "hides" a number of input arguments. To specify these // arguments explicitly, use the routine I4_TO_HAMMERSLEY_SEQUENCE instead. // // All the arguments have default values. However, if you want to // examine or change them, you may call the appropriate routine first. // // The arguments that the user may set include: // // * DIM_NUM, the spatial dimension, // Default: DIM_NUM = 1; // Required: 1 <= DIM_NUM is required. // // * STEP, the subsequence index. // Default: STEP = 0. // Required: 0 <= STEP. // // * SEED(1:DIM_NUM), the Hammersley sequence element corresponding to STEP = 0. // Default SEED = (0, 0, ... 0). // Required: 0 <= SEED(1:DIM_NUM). // // * LEAP(1:DIM_NUM), the succesive jumps in the Hammersley sequence. // Default: LEAP = (1, 1, ..., 1). // Required: 1 <= LEAP(1:DIM_NUM). // // * BASE(1:DIM_NUM), the Hammersley bases. // Default: BASE = (-N, 2, 3, 5, 7, 11, ... ). // Required: 1 < BASE(I) for a van der Corput dimension I, or // BASE(I) < 0 for a fraction sequence J/|BASE(I)|. // // // The data to be computed has two dimensions. // // The number of data items is DIM_NUM * N, where DIM_NUM is the spatial dimension // of each element of the sequence, and N is the number of elements of the sequence. // // The data is stored in a one dimensional array R. The first element of the // sequence is stored in the first DIM_NUM entries of R, followed by the DIM_NUM entries // of the second element, and so on. // // In particular, the J-th element of the sequence is stored in entries // 0+(J-1)*DIM_NUM through (DIM_NUM-1) + (J-1)*DIM_NUM. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 16 July 2004 // // Author: // // John Burkardt // // Reference: // // J M Hammersley, // Monte Carlo methods for solving multivariable problems, // Proceedings of the New York Academy of Science, // Volume 86, 1960, pages 844-874. // // Ladislav Kocis and William Whiten, // Computational Investigations of Low-Discrepancy Sequences, // ACM Transactions on Mathematical Software, // Volume 23, Number 2, 1997, pages 266-294. // // Parameters: // // Input, int N, the number of elements desired. // // Output, double R[DIM_NUM*N], the next N elements of the Hammersley sequence. // { int *base; int i; int *leap; int dim_num; int *seed; int step; if ( hammersley_DIM_NUM < 1 ) { hammersley_DIM_NUM = 1; } if ( hammersley_STEP < 0 ) { hammersley_STEP = 0; } if ( !hammersley_SEED ) { hammersley_SEED = new int[hammersley_DIM_NUM]; for ( i = 0; i < hammersley_DIM_NUM; i++ ) { hammersley_SEED[i] = 0; } } if ( !hammersley_LEAP ) { hammersley_LEAP = new int[hammersley_DIM_NUM]; for ( i = 0; i < hammersley_DIM_NUM; i++ ) { hammersley_LEAP[i] = 1; } } if ( !hammersley_BASE ) { hammersley_BASE = new int[hammersley_DIM_NUM]; hammersley_BASE[i] = -n; for ( i = 1; i < hammersley_DIM_NUM; i++ ) { hammersley_BASE[i] = prime ( i ); } } dim_num = hammersley_DIM_NUM; step = hammersley_STEP; seed = hammersley_SEED; leap = hammersley_LEAP; base = hammersley_BASE; i4_to_hammersley_sequence ( dim_num, n, step, seed, leap, base, r ); hammersley_STEP = hammersley_STEP + n; return; } //****************************************************************************80 int hammersley_step_get ( ) //****************************************************************************80 // // Purpose: // // HAMMERSLEY_STEP_GET gets the step for the leaped Hammersley subsequence. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 06 July 2004 // // Author: // // John Burkardt // // Parameters: // // Output, int HAMMERSLEY_STEP_GET, the index of the subsequence element. // { return hammersley_STEP; } //****************************************************************************80 void hammersley_step_set ( int step ) //****************************************************************************80 // // Purpose: // // HAMMERSLEY_STEP_SET sets the step for a leaped Hammersley subsequence. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 06 July 2004 // // Author: // // John Burkardt // // Parameters: // // Input, int STEP, the index of the subsequence element. // STEP must be 1 or greater. // { if ( !halham_step_check ( step ) ) { exit ( 1 ); } hammersley_STEP = step; return; } //****************************************************************************80 int i4_log_10 ( int i ) //****************************************************************************80 // // Purpose: // // I4_LOG_10 returns the whole part of the logarithm base 10 of an I4. // // Discussion: // // It should be the case that 10^I4_LOG_10(I) <= |I| < 10^(I4_LOG_10(I)+1). // (except for I = 0). // // The number of decimal digits in I is I4_LOG_10(I) + 1. // // Example: // // I I4_LOG_10(I) // // 0 0 // 1 0 // 2 0 // // 9 0 // 10 1 // 11 1 // // 99 1 // 100 2 // 101 2 // // 999 2 // 1000 3 // 1001 3 // // 9999 3 // 10000 4 // 10001 4 // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 17 June 2003 // // Author: // // John Burkardt // // Parameters: // // Input, int I, the integer. // // Output, int I4_LOG_10, the whole part of the logarithm of abs ( I ). // { int ten_pow; int value; i = abs ( i ); ten_pow = 10; value = 0; while ( ten_pow <= i ) { ten_pow = ten_pow * 10; value = value + 1; } return value; } //****************************************************************************80 int i4_min ( int i1, int i2 ) //****************************************************************************80 // // Purpose: // // I4_MIN returns the smaller 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. // { if ( i1 < i2 ) { return i1; } else { return i2; } } //****************************************************************************80 void i4_to_hammersley ( int dim_num, int step, int seed[], int leap[], int base[], double r[] ) //****************************************************************************80 // // Purpose: // // I4_TO_HAMMERSLEY computes one element of a leaped Hammersley subsequence. // // Discussion: // // The DIM_NUM-dimensional Hammersley sequence is really DIM_NUM separate // sequences, each generated by a particular base. If the base is // greater than 1, a standard 1-dimensional // van der Corput sequence is generated. But if the base is // negative, this is a signal that the much simpler sequence J/(-BASE) // is to be generated. For the standard Hammersley sequence, the // first spatial coordinate uses a base of (-N), and subsequent // coordinates use bases of successive primes (2, 3, 5, 7, 11, ...). // This program allows the user to specify any combination of bases, // included nonprimes and repeated values. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 30 September 2004 // // Author: // // John Burkardt // // Reference: // // John Hammersley, // Monte Carlo methods for solving multivariable problems, // Proceedings of the New York Academy of Science, // Volume 86, 1960, pages 844-874. // // Ladislav Kocis, William Whiten, // Computational Investigations of Low-Discrepancy Sequences, // ACM Transactions on Mathematical Software, // Volume 23, Number 2, 1997, pages 266-294. // // Parameters: // // Input, int DIM_NUM, the spatial dimension. // 1 <= DIM_NUM is required. // // Input, int STEP, the index of the subsequence element. // 0 <= STEP is required. // // Input, int SEED[DIM_NUM], the Hammersley sequence index corresponding // to STEP = 0. // 0 <= SEED(1:DIM_NUM) is required. // // Input, int LEAP[DIM_NUM], the successive jumps in the Hammersley sequence. // 1 <= LEAP(1:DIM_NUM) is required. // // Input, int BASE[DIM_NUM], the Hammersley bases. // // Output, double R[DIM_NUM], the STEP-th element of the leaped // Hammersley subsequence. // { # define FIDDLE 0.0 double base_inv; int digit; int i; int seed2; int temp; // // Check the input. // if ( !halham_dim_num_check ( dim_num ) ) { exit ( 1 ); } if ( !halham_step_check ( step ) ) { exit ( 1 ); } if ( !halham_seed_check ( dim_num, seed ) ) { exit ( 1 ); } if ( !halham_leap_check ( dim_num, seed ) ) { exit ( 1 ); } if ( !hammersley_base_check ( dim_num, base ) ) { exit ( 1 ); } // // Calculate the data. // for ( i = 0; i < dim_num; i++ ) { if ( 1 < base[i] ) { seed2 = seed[i] + step * leap[i]; r[i] = 0.0; base_inv = 1.0 / ( ( double ) base[i] ); while ( seed2 != 0 ) { digit = seed2 % base[i]; r[i] = r[i] + ( ( double ) digit ) * base_inv; base_inv = base_inv / ( ( double ) base[i] ); seed2 = seed2 / base[i]; } } // // In the following computation, the value of FIDDLE can be: // // 0, for the sequence 0/N, 1/N, ..., N-1/N // 1, for the sequence 1/N, 2/N, ..., N/N // 1/2, for the sequence 1/(2N), 3/(2N), ..., (2*N-1)/(2N) // else { temp = ( seed[i] + step * leap[i] ) % ( -base[i] ); r[i] = ( ( double ) ( temp ) + FIDDLE ) / ( double ) ( -base[i] ); } } return; # undef FIDDLE } //****************************************************************************80 void i4_to_hammersley_sequence ( int dim_num, int n, int step, int seed[], int leap[], int base[], double r[] ) //****************************************************************************80 // // Purpose: // // I4_TO_HAMMERSLEY_SEQUENCE computes N elements of a leaped Hammersley subsequence. // // Discussion: // // The DIM_NUM-dimensional Hammersley sequence is really DIM_NUM separate // sequences, each generated by a particular base. If the base is // greater than 1, a standard 1-dimensional // van der Corput sequence is generated. But if the base is // negative, this is a signal that the much simpler sequence J/(-BASE) // is to be generated. For the standard Hammersley sequence, the // first spatial coordinate uses a base of (-N), and subsequent // coordinates use bases of successive primes (2, 3, 5, 7, 11, ...). // This program allows the user to specify any combination of bases, // included nonprimes and repeated values. // // This routine selects elements of a "leaped" subsequence of the // Hammersley sequence. The subsequence elements are indexed by a // quantity called STEP, which starts at 0. The STEP-th subsequence // element is simply element // // SEED(1:DIM_NUM) + STEP * LEAP(1:DIM_NUM) // // of the original Hammersley sequence. // // // The data to be computed has two dimensions. // // The number of data items is DIM_NUM * N, where DIM_NUM is the spatial // dimension of each element of the sequence, and N is the number of // elements of the sequence. // // The data is stored in a one dimensional array R. The first element // of the sequence is stored in the first DIM_NUM entries of R, followed // by the DIM_NUM entries of the second element, and so on. // // In particular, the J-th element of the sequence is stored in entries // 0+(J-1)*DIM_NUM through (DIM_NUM-1) + (J-1)*DIM_NUM. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 30 September 2004 // // Author: // // John Burkardt // // Reference: // // John Hammersley, // Monte Carlo methods for solving multivariable problems, // Proceedings of the New York Academy of Science, // Volume 86, 1960, pages 844-874. // // Ladislav Kocis, William Whiten, // Computational Investigations of Low-Discrepancy Sequences, // ACM Transactions on Mathematical Software, // Volume 23, Number 2, 1997, pages 266-294. // // Parameters: // // Input, int DIM_NUM, the spatial dimension. // // Input, int N, the number of elements of the sequence. // // Input, int STEP, the index of the subsequence element. // 0 <= STEP is required // // Input, int SEED[DIM_NUM], the Hammersley sequence index corresponding // to STEP = 0. // // Input, int LEAP[DIM_NUM], the succesive jumps in the Hammersley sequence. // // Input, int BASE[DIM_NUM], the Hammersley bases. // // Output, double R[DIM_NUM*N], the next N elements of the // leaped Hammersley subsequence, beginning with element STEP. // { # define FIDDLE 0.0 double base_inv; int digit; int i; int j; int *seed2; int temp; // // Check the input. // if ( !halham_dim_num_check ( dim_num ) ) { exit ( 1 ); } if ( !halham_n_check ( n ) ) { exit ( 1 ); } if ( !halham_step_check ( step ) ) { exit ( 1 ); } if ( !halham_seed_check ( dim_num, seed ) ) { exit ( 1 ); } if ( !halham_leap_check ( dim_num, leap ) ) { exit ( 1 ); } if ( !hammersley_base_check ( dim_num, base ) ) { exit ( 1 ); } // // Calculate the data. // seed2 = new int[n]; for ( i = 0; i < dim_num; i++ ) { if ( 1 < base[i] ) { for ( j = 0; j < n; j++ ) { seed2[j] = seed[i] + ( step + j ) * leap[i]; } for ( j = 0; j < n; j++ ) { r[i+j*dim_num] = 0.0; } for ( j = 0; j < n; j++ ) { base_inv = 1.0 / ( ( double ) base[i] ); while ( seed2[j] != 0 ) { digit = seed2[j] % base[i]; r[i+j*dim_num] = r[i+j*dim_num] + ( ( double ) digit ) * base_inv; base_inv = base_inv / ( ( double ) base[i] ); seed2[j] = seed2[j] / base[i]; } } } // // In the following computation, the value of FIDDLE can be: // // 0, for the sequence 0/N, 1/N, ..., N-1/N // 1, for the sequence 1/N, 2/N, ..., N/N // 1/2, for the sequence 1/(2N), 3/(2N), ..., (2*N-1)/(2N) // else { for ( j = 0; j < n; j++ ) { temp = ( seed[i] + ( step + j ) * leap[i] ) % ( -base[i] ); r[i+j*dim_num] = ( ( double ) ( temp ) + FIDDLE ) / ( double ) ( -base[i] ); } } } delete [] seed2; return; # undef FIDDLE } //****************************************************************************80 char *i4_to_s ( int i ) //****************************************************************************80 // // Purpose: // // I4_TO_S converts an I4 to a string. // // Example: // // INTVAL S // // 1 1 // -1 -1 // 0 0 // 1952 1952 // 123456 123456 // 1234567 1234567 // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 13 March 2004 // // Author: // // John Burkardt // // Parameters: // // Input, int I, an integer to be converted. // // Output, char *I4_TO_S, the representation of the integer. // { int digit; int j; int length; int ten_power; char *s; length = i4_log_10 ( i ); ten_power = ( int ) pow ( ( double ) 10, ( double ) length ); if ( i < 0 ) { length = length + 1; } // // Add one position for the trailing null. // length = length + 1; s = new char[length]; if ( i == 0 ) { s[0] = '0'; s[1] = '\0'; return s; } // // Now take care of the sign. // j = 0; if ( i < 0 ) { s[j] = '-'; j = j + 1; i = abs ( i ); } // // Find the leading digit of I, strip it off, and stick it into the string. // while ( 0 < ten_power ) { digit = i / ten_power; s[j] = digit_to_ch ( digit ); j = j + 1; i = i - digit * ten_power; ten_power = ten_power / 10; } // // Tack on the trailing NULL. // s[j] = '\0'; j = j + 1; return s; } //****************************************************************************80 void i4vec_transpose_print ( int n, int a[], char *title ) //****************************************************************************80 // // Purpose: // // I4VEC_TRANSPOSE_PRINT prints an I4VEC "transposed". // // Example: // // A = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 } // TITLE = "My vector: " // // My vector: 1 2 3 4 5 // 6 7 8 9 10 // 11 // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 03 July 2004 // // 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 to be printed first. // TITLE may be blank or NULL. // { int i; int ihi; int ilo; int title_len; if ( 0 < s_len_trim ( title ) ) { title_len = strlen ( title ); for ( ilo = 1; ilo <= n; ilo = ilo + 5 ) { ihi = i4_min ( ilo + 5 - 1, n ); if ( ilo == 1 ) { cout << title; } else { for ( i = 1; i <= title_len; i++ ) { cout << " "; } } for ( i = ilo; i <= ihi; i++ ) { cout << setw(12) << a[i-1]; } cout << "\n"; } } else { for ( ilo = 1; ilo <= n; ilo = ilo + 5 ) { ihi = i4_min ( ilo + 5 - 1, n ); for ( i = ilo; i <= ihi; i++ ) { cout << setw(12) << a[i-1]; } cout << "\n"; } } return; } //****************************************************************************80 int prime ( int n ) //****************************************************************************80 // // Purpose: // // PRIME returns any of the first PRIME_MAX prime numbers. // // Discussion: // // PRIME_MAX is 1600, and the largest prime stored is 13499. // // Thanks to Bart Vandewoestyne for pointing out a typo, 18 February 2005. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 18 February 2005 // // Author: // // John Burkardt // // Reference: // // Milton Abramowitz and Irene Stegun, // Handbook of Mathematical Functions, // US Department of Commerce, 1964, pages 870-873. // // Daniel Zwillinger, // CRC Standard Mathematical Tables and Formulae, // 30th Edition, // CRC Press, 1996, pages 95-98. // // Parameters: // // Input, int N, the index of the desired prime number. // In general, is should be true that 0 <= N <= PRIME_MAX. // N = -1 returns PRIME_MAX, the index of the largest prime available. // N = 0 is legal, returning PRIME = 1. // // Output, int PRIME, the N-th prime. If N is out of range, PRIME // is returned as -1. // { # define PRIME_MAX 1600 int npvec[PRIME_MAX] = { 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 281, 283, 293, 307, 311, 313, 317, 331, 337, 347, 349, 353, 359, 367, 373, 379, 383, 389, 397, 401, 409, 419, 421, 431, 433, 439, 443, 449, 457, 461, 463, 467, 479, 487, 491, 499, 503, 509, 521, 523, 541, 547, 557, 563, 569, 571, 577, 587, 593, 599, 601, 607, 613, 617, 619, 631, 641, 643, 647, 653, 659, 661, 673, 677, 683, 691, 701, 709, 719, 727, 733, 739, 743, 751, 757, 761, 769, 773, 787, 797, 809, 811, 821, 823, 827, 829, 839, 853, 857, 859, 863, 877, 881, 883, 887, 907, 911, 919, 929, 937, 941, 947, 953, 967, 971, 977, 983, 991, 997, 1009, 1013, 1019, 1021, 1031, 1033, 1039, 1049, 1051, 1061, 1063, 1069, 1087, 1091, 1093, 1097, 1103, 1109, 1117, 1123, 1129, 1151, 1153, 1163, 1171, 1181, 1187, 1193, 1201, 1213, 1217, 1223, 1229, 1231, 1237, 1249, 1259, 1277, 1279, 1283, 1289, 1291, 1297, 1301, 1303, 1307, 1319, 1321, 1327, 1361, 1367, 1373, 1381, 1399, 1409, 1423, 1427, 1429, 1433, 1439, 1447, 1451, 1453, 1459, 1471, 1481, 1483, 1487, 1489, 1493, 1499, 1511, 1523, 1531, 1543, 1549, 1553, 1559, 1567, 1571, 1579, 1583, 1597, 1601, 1607, 1609, 1613, 1619, 1621, 1627, 1637, 1657, 1663, 1667, 1669, 1693, 1697, 1699, 1709, 1721, 1723, 1733, 1741, 1747, 1753, 1759, 1777, 1783, 1787, 1789, 1801, 1811, 1823, 1831, 1847, 1861, 1867, 1871, 1873, 1877, 1879, 1889, 1901, 1907, 1913, 1931, 1933, 1949, 1951, 1973, 1979, 1987, 1993, 1997, 1999, 2003, 2011, 2017, 2027, 2029, 2039, 2053, 2063, 2069, 2081, 2083, 2087, 2089, 2099, 2111, 2113, 2129, 2131, 2137, 2141, 2143, 2153, 2161, 2179, 2203, 2207, 2213, 2221, 2237, 2239, 2243, 2251, 2267, 2269, 2273, 2281, 2287, 2293, 2297, 2309, 2311, 2333, 2339, 2341, 2347, 2351, 2357, 2371, 2377, 2381, 2383, 2389, 2393, 2399, 2411, 2417, 2423, 2437, 2441, 2447, 2459, 2467, 2473, 2477, 2503, 2521, 2531, 2539, 2543, 2549, 2551, 2557, 2579, 2591, 2593, 2609, 2617, 2621, 2633, 2647, 2657, 2659, 2663, 2671, 2677, 2683, 2687, 2689, 2693, 2699, 2707, 2711, 2713, 2719, 2729, 2731, 2741, 2749, 2753, 2767, 2777, 2789, 2791, 2797, 2801, 2803, 2819, 2833, 2837, 2843, 2851, 2857, 2861, 2879, 2887, 2897, 2903, 2909, 2917, 2927, 2939, 2953, 2957, 2963, 2969, 2971, 2999, 3001, 3011, 3019, 3023, 3037, 3041, 3049, 3061, 3067, 3079, 3083, 3089, 3109, 3119, 3121, 3137, 3163, 3167, 3169, 3181, 3187, 3191, 3203, 3209, 3217, 3221, 3229, 3251, 3253, 3257, 3259, 3271, 3299, 3301, 3307, 3313, 3319, 3323, 3329, 3331, 3343, 3347, 3359, 3361, 3371, 3373, 3389, 3391, 3407, 3413, 3433, 3449, 3457, 3461, 3463, 3467, 3469, 3491, 3499, 3511, 3517, 3527, 3529, 3533, 3539, 3541, 3547, 3557, 3559, 3571, 3581, 3583, 3593, 3607, 3613, 3617, 3623, 3631, 3637, 3643, 3659, 3671, 3673, 3677, 3691, 3697, 3701, 3709, 3719, 3727, 3733, 3739, 3761, 3767, 3769, 3779, 3793, 3797, 3803, 3821, 3823, 3833, 3847, 3851, 3853, 3863, 3877, 3881, 3889, 3907, 3911, 3917, 3919, 3923, 3929, 3931, 3943, 3947, 3967, 3989, 4001, 4003, 4007, 4013, 4019, 4021, 4027, 4049, 4051, 4057, 4073, 4079, 4091, 4093, 4099, 4111, 4127, 4129, 4133, 4139, 4153, 4157, 4159, 4177, 4201, 4211, 4217, 4219, 4229, 4231, 4241, 4243, 4253, 4259, 4261, 4271, 4273, 4283, 4289, 4297, 4327, 4337, 4339, 4349, 4357, 4363, 4373, 4391, 4397, 4409, 4421, 4423, 4441, 4447, 4451, 4457, 4463, 4481, 4483, 4493, 4507, 4513, 4517, 4519, 4523, 4547, 4549, 4561, 4567, 4583, 4591, 4597, 4603, 4621, 4637, 4639, 4643, 4649, 4651, 4657, 4663, 4673, 4679, 4691, 4703, 4721, 4723, 4729, 4733, 4751, 4759, 4783, 4787, 4789, 4793, 4799, 4801, 4813, 4817, 4831, 4861, 4871, 4877, 4889, 4903, 4909, 4919, 4931, 4933, 4937, 4943, 4951, 4957, 4967, 4969, 4973, 4987, 4993, 4999, 5003, 5009, 5011, 5021, 5023, 5039, 5051, 5059, 5077, 5081, 5087, 5099, 5101, 5107, 5113, 5119, 5147, 5153, 5167, 5171, 5179, 5189, 5197, 5209, 5227, 5231, 5233, 5237, 5261, 5273, 5279, 5281, 5297, 5303, 5309, 5323, 5333, 5347, 5351, 5381, 5387, 5393, 5399, 5407, 5413, 5417, 5419, 5431, 5437, 5441, 5443, 5449, 5471, 5477, 5479, 5483, 5501, 5503, 5507, 5519, 5521, 5527, 5531, 5557, 5563, 5569, 5573, 5581, 5591, 5623, 5639, 5641, 5647, 5651, 5653, 5657, 5659, 5669, 5683, 5689, 5693, 5701, 5711, 5717, 5737, 5741, 5743, 5749, 5779, 5783, 5791, 5801, 5807, 5813, 5821, 5827, 5839, 5843, 5849, 5851, 5857, 5861, 5867, 5869, 5879, 5881, 5897, 5903, 5923, 5927, 5939, 5953, 5981, 5987, 6007, 6011, 6029, 6037, 6043, 6047, 6053, 6067, 6073, 6079, 6089, 6091, 6101, 6113, 6121, 6131, 6133, 6143, 6151, 6163, 6173, 6197, 6199, 6203, 6211, 6217, 6221, 6229, 6247, 6257, 6263, 6269, 6271, 6277, 6287, 6299, 6301, 6311, 6317, 6323, 6329, 6337, 6343, 6353, 6359, 6361, 6367, 6373, 6379, 6389, 6397, 6421, 6427, 6449, 6451, 6469, 6473, 6481, 6491, 6521, 6529, 6547, 6551, 6553, 6563, 6569, 6571, 6577, 6581, 6599, 6607, 6619, 6637, 6653, 6659, 6661, 6673, 6679, 6689, 6691, 6701, 6703, 6709, 6719, 6733, 6737, 6761, 6763, 6779, 6781, 6791, 6793, 6803, 6823, 6827, 6829, 6833, 6841, 6857, 6863, 6869, 6871, 6883, 6899, 6907, 6911, 6917, 6947, 6949, 6959, 6961, 6967, 6971, 6977, 6983, 6991, 6997, 7001, 7013, 7019, 7027, 7039, 7043, 7057, 7069, 7079, 7103, 7109, 7121, 7127, 7129, 7151, 7159, 7177, 7187, 7193, 7207, 7211, 7213, 7219, 7229, 7237, 7243, 7247, 7253, 7283, 7297, 7307, 7309, 7321, 7331, 7333, 7349, 7351, 7369, 7393, 7411, 7417, 7433, 7451, 7457, 7459, 7477, 7481, 7487, 7489, 7499, 7507, 7517, 7523, 7529, 7537, 7541, 7547, 7549, 7559, 7561, 7573, 7577, 7583, 7589, 7591, 7603, 7607, 7621, 7639, 7643, 7649, 7669, 7673, 7681, 7687, 7691, 7699, 7703, 7717, 7723, 7727, 7741, 7753, 7757, 7759, 7789, 7793, 7817, 7823, 7829, 7841, 7853, 7867, 7873, 7877, 7879, 7883, 7901, 7907, 7919, 7927, 7933, 7937, 7949, 7951, 7963, 7993, 8009, 8011, 8017, 8039, 8053, 8059, 8069, 8081, 8087, 8089, 8093, 8101, 8111, 8117, 8123, 8147, 8161, 8167, 8171, 8179, 8191, 8209, 8219, 8221, 8231, 8233, 8237, 8243, 8263, 8269, 8273, 8287, 8291, 8293, 8297, 8311, 8317, 8329, 8353, 8363, 8369, 8377, 8387, 8389, 8419, 8423, 8429, 8431, 8443, 8447, 8461, 8467, 8501, 8513, 8521, 8527, 8537, 8539, 8543, 8563, 8573, 8581, 8597, 8599, 8609, 8623, 8627, 8629, 8641, 8647, 8663, 8669, 8677, 8681, 8689, 8693, 8699, 8707, 8713, 8719, 8731, 8737, 8741, 8747, 8753, 8761, 8779, 8783, 8803, 8807, 8819, 8821, 8831, 8837, 8839, 8849, 8861, 8863, 8867, 8887, 8893, 8923, 8929, 8933, 8941, 8951, 8963, 8969, 8971, 8999, 9001, 9007, 9011, 9013, 9029, 9041, 9043, 9049, 9059, 9067, 9091, 9103, 9109, 9127, 9133, 9137, 9151, 9157, 9161, 9173, 9181, 9187, 9199, 9203, 9209, 9221, 9227, 9239, 9241, 9257, 9277, 9281, 9283, 9293, 9311, 9319, 9323, 9337, 9341, 9343, 9349, 9371, 9377, 9391, 9397, 9403, 9413, 9419, 9421, 9431, 9433, 9437, 9439, 9461, 9463, 9467, 9473, 9479, 9491, 9497, 9511, 9521, 9533, 9539, 9547, 9551, 9587, 9601, 9613, 9619, 9623, 9629, 9631, 9643, 9649, 9661, 9677, 9679, 9689, 9697, 9719, 9721, 9733, 9739, 9743, 9749, 9767, 9769, 9781, 9787, 9791, 9803, 9811, 9817, 9829, 9833, 9839, 9851, 9857, 9859, 9871, 9883, 9887, 9901, 9907, 9923, 9929, 9931, 9941, 9949, 9967, 9973,10007, 10009,10037,10039,10061,10067,10069,10079,10091,10093,10099, 10103,10111,10133,10139,10141,10151,10159,10163,10169,10177, 10181,10193,10211,10223,10243,10247,10253,10259,10267,10271, 10273,10289,10301,10303,10313,10321,10331,10333,10337,10343, 10357,10369,10391,10399,10427,10429,10433,10453,10457,10459, 10463,10477,10487,10499,10501,10513,10529,10531,10559,10567, 10589,10597,10601,10607,10613,10627,10631,10639,10651,10657, 10663,10667,10687,10691,10709,10711,10723,10729,10733,10739, 10753,10771,10781,10789,10799,10831,10837,10847,10853,10859, 10861,10867,10883,10889,10891,10903,10909,10937,10939,10949, 10957,10973,10979,10987,10993,11003,11027,11047,11057,11059, 11069,11071,11083,11087,11093,11113,11117,11119,11131,11149, 11159,11161,11171,11173,11177,11197,11213,11239,11243,11251, 11257,11261,11273,11279,11287,11299,11311,11317,11321,11329, 11351,11353,11369,11383,11393,11399,11411,11423,11437,11443, 11447,11467,11471,11483,11489,11491,11497,11503,11519,11527, 11549,11551,11579,11587,11593,11597,11617,11621,11633,11657, 11677,11681,11689,11699,11701,11717,11719,11731,11743,11777, 11779,11783,11789,11801,11807,11813,11821,11827,11831,11833, 11839,11863,11867,11887,11897,11903,11909,11923,11927,11933, 11939,11941,11953,11959,11969,11971,11981,11987,12007,12011, 12037,12041,12043,12049,12071,12073,12097,12101,12107,12109, 12113,12119,12143,12149,12157,12161,12163,12197,12203,12211, 12227,12239,12241,12251,12253,12263,12269,12277,12281,12289, 12301,12323,12329,12343,12347,12373,12377,12379,12391,12401, 12409,12413,12421,12433,12437,12451,12457,12473,12479,12487, 12491,12497,12503,12511,12517,12527,12539,12541,12547,12553, 12569,12577,12583,12589,12601,12611,12613,12619,12637,12641, 12647,12653,12659,12671,12689,12697,12703,12713,12721,12739, 12743,12757,12763,12781,12791,12799,12809,12821,12823,12829, 12841,12853,12889,12893,12899,12907,12911,12917,12919,12923, 12941,12953,12959,12967,12973,12979,12983,13001,13003,13007, 13009,13033,13037,13043,13049,13063,13093,13099,13103,13109, 13121,13127,13147,13151,13159,13163,13171,13177,13183,13187, 13217,13219,13229,13241,13249,13259,13267,13291,13297,13309, 13313,13327,13331,13337,13339,13367,13381,13397,13399,13411, 13417,13421,13441,13451,13457,13463,13469,13477,13487,13499 }; if ( n == -1 ) { return PRIME_MAX; } else if ( n == 0 ) { return 1; } else if ( n <= PRIME_MAX ) { return npvec[n-1]; } else { cout << "\n"; cout << "PRIME - Fatal error!\n"; cout << " Unexpected input value of n = " << n << "\n"; exit ( 1 ); } return 0; # undef PRIME_MAX } //****************************************************************************80 double r8_epsilon ( ) //****************************************************************************80 // // Purpose: // // R8_EPSILON returns the R8 roundoff unit. // // Discussion: // // The roundoff unit is a number R which is a power of 2 with the // property that, to the precision of the computer's arithmetic, // 1 < 1 + R // but // 1 = ( 1 + R / 2 ) // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 01 September 2012 // // Author: // // John Burkardt // // Parameters: // // Output, double R8_EPSILON, the R8 round-off unit. // { const double value = 2.220446049250313E-016; return value; } //****************************************************************************80 double r8vec_dot_product ( int n, double *r1, double *r2 ) //****************************************************************************80 // // Purpose: // // R8VEC_DOT_PRODUCT returns the dot product of two R8VEC's. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 01 March 2003 // // Author: // // John Burkardt // // Parameters: // // Input, int N, the number of entries in the arrays. // // Input, double *R1, R2, pointers to the first entries of the arrays. // // Output, double R8VEC_DOT_PRODUCT, the dot product of the two arrays. // { int i; double dot; dot = 0.0; for ( i = 0; i < n; i++ ) { dot = dot + (*r1) * (*r2); r1 = r1 + 1; r2 = r2 + 1; } return dot; } //****************************************************************************80 double r8vec_norm_l2 ( int n, double a[] ) //****************************************************************************80 // // Purpose: // // R8VEC_NORM_L2 returns the L2 norm of an R8VEC. // // Discussion: // // The vector L2 norm is defined as: // // value = sqrt ( sum ( 1 <= I <= N ) A(I)**2 ). // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 01 March 2003 // // Author: // // John Burkardt // // Parameters: // // Input, int N, the number of entries in A. // // Input, double A[N], the vector whose L2 norm is desired. // // Output, double R8VEC_NORM_L2, the L2 norm of A. // { int i; double v; v = 0.0; for ( i = 0; i < n; i++ ) { v = v + a[i] * a[i]; } v = sqrt ( v ); return v; } //****************************************************************************80 int s_len_trim ( char *s ) //****************************************************************************80 // // Purpose: // // S_LEN_TRIM returns the length of a string to the last nonblank. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 26 April 2003 // // 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 != ' ' ) { return n; } t--; n--; } return n; } //****************************************************************************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 } //****************************************************************************80 char *timestring ( ) //****************************************************************************80 // // Purpose: // // TIMESTRING returns the current YMDHMS date as a string. // // Example: // // May 31 2001 09:45:54 AM // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 24 September 2003 // // Author: // // John Burkardt // // Parameters: // // Output, char *TIMESTRING, a string containing the current YMDHMS date. // { # define TIME_SIZE 40 const struct tm *tm; size_t len; time_t now; char *s; now = time ( NULL ); tm = localtime ( &now ); s = new char[TIME_SIZE]; len = strftime ( s, TIME_SIZE, "%d %B %Y %I:%M:%S %p", tm ); return s; # undef TIME_SIZE } //****************************************************************************80 void u1_to_sphere_unit_2d ( double u[], double x[2] ) //****************************************************************************80 // // Purpose: // // U1_TO_SPHERE_UNIT_2D maps a point in the unit interval onto the circle in 2D. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 06 July 2004 // // Author: // // John Burkardt // // Parameters: // // Input, double U[1], a point in the unit interval. // // Output, double X[2], the corresponding point on the unit circle. // { double angle; double pi = 3.141592653589793; angle = 2.0 * pi * u[0]; x[0] = cos ( angle ); x[1] = sin ( angle ); return; } //****************************************************************************80 void u2_to_ball_unit_2d ( double u[2], double x[2] ) //****************************************************************************80 // // Purpose: // // U2_TO_BALL_UNIT_2D maps points from the unit box to the unit ball in 2D. // // Modified: // // 06 July 2004 // // Author: // // John Burkardt // // Parameters: // // Input, double U[2], a point in the unit box. // // Output, double X[2], the corresponding point in the unit ball. // { double pi = 3.141592653589793; double r; double theta; r = sqrt ( u[0] ); theta = 2.0 * pi * u[1]; x[0] = r * cos ( theta ); x[1] = r * sin ( theta ); return; } //****************************************************************************80 void u2_to_sphere_unit_3d ( double u[2], double x[3] ) //****************************************************************************80 // // Purpose: // // U2_TO_SPHERE_UNIT_3D maps a point in the unit box to the unit sphere in 3D. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 06 July 2004 // // Author: // // John Burkardt // // Parameters: // // Input, double U[2], a point in the unit box. // // Output, double X[3], the corresponding point on the unit sphere. // { double phi; double pi = 3.141592653589793; double theta; double vdot; // // Pick a uniformly random VDOT, which must be between -1 and 1. // This represents the dot product of the random vector with the Z unit vector. // // Note: this works because the surface area of the sphere between // Z and Z + dZ is independent of Z. So choosing Z uniformly chooses // a patch of area uniformly. // vdot = 2.0 * u[0] - 1.0; phi = arc_cosine ( vdot ); // // Pick a uniformly random rotation between 0 and 2 Pi around the // axis of the Z vector. // theta = 2.0 * pi * u[1]; x[0] = cos ( theta ) * sin ( phi ); x[1] = sin ( theta ) * sin ( phi ); x[2] = cos ( phi ); return; # undef PI } //****************************************************************************80 void u3_to_ball_unit_3d ( double u[3], double x[3] ) //****************************************************************************80 // // Purpose: // // U3_TO_BALL_UNIT_3D maps points from the unit box to the unit ball in 3D. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 06 July 2004 // // Author: // // John Burkardt // // Parameters: // // Input, double U[3], a point in the unit box. // // Output, double X[3], the corresponding point in the unit ball. // { double phi; double pi = 3.141592653589793; double r; double theta; double vdot; // // Pick a uniformly random VDOT, which must be between -1 and 1. // This represents the dot product of the random vector with the Z unit vector. // // Note: this works because the surface area of the sphere between // Z and Z + dZ is independent of Z. So choosing Z uniformly chooses // a patch of area uniformly. // vdot = 2.0 * u[0] - 1.0; phi = arc_cosine ( vdot ); // // Pick a uniformly random rotation between 0 and 2 Pi around the // axis of the Z vector. // theta = 2.0 * pi * u[1]; // // Pick a random radius R. // r = pow ( ( double ) u[2], ( double ) ( 1.0 / 3.0 ) ); x[0] = r * cos ( theta ) * sin ( phi ); x[1] = r * sin ( theta ) * sin ( phi ); x[2] = r * cos ( phi ); return; }