# include # include # include # include # include # include using namespace std; # include "r8blt.hpp" //****************************************************************************80 int i4_log_10 ( int i ) //****************************************************************************80 // // Purpose: // // I4_LOG_10 returns the integer part of the logarithm base 10 of ABS(X). // // Example: // // I I4_LOG_10 // ----- -------- // 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 // // Discussion: // // I4_LOG_10 ( I ) + 1 is the number of decimal digits in I. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 04 January 2004 // // Author: // // John Burkardt // // Parameters: // // Input, int I, the number whose logarithm base 10 is desired. // // Output, int I4_LOG_10, the integer part of the logarithm base 10 of // the absolute value of X. // { int i_abs; int ten_pow; int value; if ( i == 0 ) { value = 0; } else { value = 0; ten_pow = 10; i_abs = abs ( i ); while ( ten_pow <= i_abs ) { value = value + 1; ten_pow = ten_pow * 10; } } return value; } //****************************************************************************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 int i4_power ( int i, int j ) //****************************************************************************80 // // Purpose: // // I4_POWER returns the value of I^J. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 01 April 2004 // // Author: // // John Burkardt // // Parameters: // // Input, int I, J, the base and the power. J should be nonnegative. // // Output, int I4_POWER, the value of I^J. // { int k; int value; if ( j < 0 ) { if ( i == 1 ) { value = 1; } else if ( i == 0 ) { cerr << "\n"; cerr << "I4_POWER - Fatal error!\n"; cerr << " I^J requested, with I = 0 and J negative.\n"; exit ( 1 ); } else { value = 0; } } else if ( j == 0 ) { if ( i == 0 ) { cerr << "\n"; cerr << "I4_POWER - Fatal error!\n"; cerr << " I^J requested, with I = 0 and J = 0.\n"; exit ( 1 ); } else { value = 1; } } else if ( j == 1 ) { value = i; } else { value = 1; for ( k = 1; k <= j; k++ ) { value = value * i; } } return value; } //****************************************************************************80 double r8_uniform_01 ( int &seed ) //****************************************************************************80 // // Purpose: // // R8_UNIFORM_01 returns a unit pseudorandom R8. // // Discussion: // // This routine implements the recursion // // seed = ( 16807 * seed ) mod ( 2^31 - 1 ) // u = seed / ( 2^31 - 1 ) // // The integer arithmetic never requires more than 32 bits, // including a sign bit. // // If the initial seed is 12345, then the first three computations are // // Input Output R8_UNIFORM_01 // SEED SEED // // 12345 207482415 0.096616 // 207482415 1790989824 0.833995 // 1790989824 2035175616 0.947702 // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 09 April 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/output, int &SEED, the "seed" value. Normally, this // value should not be 0. On output, SEED has been updated. // // Output, double R8_UNIFORM_01, a new pseudorandom variate, // strictly between 0 and 1. // { const int i4_huge = 2147483647; int k; double r; if ( seed == 0 ) { cerr << "\n"; cerr << "R8_UNIFORM_01 - Fatal error!\n"; cerr << " Input value of SEED = 0.\n"; exit ( 1 ); } k = seed / 127773; seed = 16807 * ( seed - k * 127773 ) - k * 2836; if ( seed < 0 ) { seed = seed + i4_huge; } r = ( double ) ( seed ) * 4.656612875E-10; return r; } //****************************************************************************80 double r8blt_det ( int n, int ml, double a[] ) //****************************************************************************80 // // Purpose: // // R8BLT_DET computes the determinant of an R8BLT matrix. // // Discussion: // // The R8BLT storage format is appropriate for a banded lower triangular matrix. // The matrix is assumed to be zero below the ML-th subdiagonal. // The matrix is stored in an ML+1 by N array, in which the diagonal // appears in the first row, followed by successive subdiagonals. // Columns are preserved. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 12 October 2003 // // Author: // // John Burkardt // // Parameters: // // Input, int N, the order of the matrix. // // Input, int ML, the lower bandwidth. // // Input, double A[(ML+1)*N], the R8BLT matrix. // // Output, double R8BLT_DET, the determinant of A. // { double det; int j; det = 1.0; for ( j = 0; j < n; j++ ) { det = det * a[0+j*(ml+1)]; } return det; } //****************************************************************************80 double *r8blt_indicator ( int n, int ml ) //****************************************************************************80 // // Purpose: // // R8BLT_INDICATOR sets up an R8BLT indicator matrix. // // Discussion: // // The R8BLT storage format is appropriate for a banded lower triangular matrix. // The matrix is assumed to be zero below the ML-th subdiagonal. // The matrix is stored in an ML+1 by N array, in which the diagonal // appears in the first row, followed by successive subdiagonals. // Columns are preserved. // // Example: // // N = 5, ML = 2 // // A11 0 0 0 0 // A21 A22 0 0 0 // A31 A32 A33 0 0 // 0 A42 A43 A44 0 // 0 0 A53 A54 A55 // --- --- // --- // // The indicator matrix is stored as: // // 11 22 33 44 55 // 21 32 43 54 0 // 31 42 53 0 0 // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 21 January 2004 // // Author: // // John Burkardt // // Parameters: // // Input, int N, the number of columns of the matrix. // // Input, int ML, the lower bandwidth. // // Output, double R8BLT_INDICATOR[(ML+1)*N], the R8BLT matrix. // { double *a; int fac; int i; int j; int jlo; a = new double[(ml+1)*n]; fac = i4_power ( 10, i4_log_10 ( n ) + 1 ); for ( i = 1; i <= n; i++ ) { jlo = i4_max ( 1, i - ml ); for ( j = jlo; j <= i; j++ ) { a[i-j+(j-1)*(ml+1)] = ( double ) ( fac * i + j ); } } // // The junk entries can be thought of as corresponding to // elements of a phantom portion of the matrix. // for ( i = n; i < n + ml; i++ ) { for ( j = i - ml; j < n; j++ ) { a[i-j+j*(ml+1)] = 0.0; } } return a; } //****************************************************************************80 double *r8blt_mtv ( int n, int ml, double a[], double x[] ) //****************************************************************************80 // // Purpose: // // R8BLT_MTV multiplies a vector by an R8BLT matrix. // // Discussion: // // The R8BLT storage format is appropriate for a banded lower triangular matrix. // The matrix is assumed to be zero below the ML-th subdiagonal. // The matrix is stored in an ML+1 by N array, in which the diagonal // appears in the first row, followed by successive subdiagonals. // Columns are preserved. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 12 October 2003 // // Author: // // John Burkardt // // Parameters: // // Input, int N, the order of the matrix. // // Input, int ML, the lower bandwidth. // // Input, double A[(ML+1)*N], the R8BLT matrix. // // Input, double X[N], the vector to be multiplied by A. // // Output, double R8BLT_MTV[N], the product X*A. // { double *b; int i; int j; int jhi; int jlo; b = r8vec_zeros_new ( n ); for ( i = 0; i < n; i++ ) { jlo = i4_max ( 0, i - ml ); jhi = i; for ( j = jlo; j <= jhi; j++ ) { b[j] = b[j] + x[i] * a[i-j+j*(ml+1)]; } } return b; } //****************************************************************************80 double *r8blt_mv ( int n, int ml, double a[], double x[] ) //****************************************************************************80 // // Purpose: // // R8BLT_MV multiplies an R8BLT matrix times a vector. // // Discussion: // // The R8BLT storage format is appropriate for a banded lower triangular matrix. // The matrix is assumed to be zero below the ML-th subdiagonal. // The matrix is stored in an ML+1 by N array, in which the diagonal // appears in the first row, followed by successive subdiagonals. // Columns are preserved. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 22 January 2004 // // Author: // // John Burkardt // // Parameters: // // Input, int N, the order of the matrix. // // Input, int ML, the lower bandwidth. // // Input, double A[(ML+1)*N], the R8BLT matrix. // // Input, double X[N], the vector to be multiplied by A. // // Output, double R8BLT_MV[N], the product A * x. // { double *b; int i; int j; int jhi; int jlo; b = r8vec_zeros_new ( n ); for ( i = 0; i < n; i++ ) { jlo = i4_max ( 0, i - ml ); jhi = i; for ( j = jlo; j <= jhi; j++ ) { b[i] = b[i] + a[i-j+j*(ml+1)] * x[j]; } } return b; } //****************************************************************************80 void r8blt_print ( int n, int ml, double a[], string title ) //****************************************************************************80 // // Purpose: // // R8BLT_PRINT prints an R8BLT matrix. // // Discussion: // // The R8BLT storage format is appropriate for a banded lower triangular matrix. // The matrix is assumed to be zero below the ML-th subdiagonal. // The matrix is stored in an ML+1 by N array, in which the diagonal // appears in the first row, followed by successive subdiagonals. // Columns are preserved. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 06 April 2006 // // Author: // // John Burkardt // // Parameters: // // Input, int N, the order of the matrix. // // Input, int ML, the lower bandwidth. // // Input, double A[(ML+1)*N], the R8BLT matrix. // // Input, string TITLE, a title. // { r8blt_print_some ( n, ml, a, 1, 1, n, n, title ); return; } //****************************************************************************80 void r8blt_print_some ( int n, int ml, double a[], int ilo, int jlo, int ihi, int jhi, string title ) //****************************************************************************80 // // Purpose: // // R8BLT_PRINT_SOME prints some of an R8BLT matrix. // // Discussion: // // The R8BLT storage format is appropriate for a banded lower triangular matrix. // The matrix is assumed to be zero below the ML-th subdiagonal. // The matrix is stored in an ML+1 by N array, in which the diagonal // appears in the first row, followed by successive subdiagonals. // Columns are preserved. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 06 April 2006 // // Author: // // John Burkardt // // Parameters: // // Input, int N, the order of the matrix. // // Input, int ML, the lower bandwidth. // // Input, double A[(ML+1)*N], the R8BLT matrix. // // Input, int ILO, JLO, IHI, JHI, designate the first row and // column, and the last row and column to be printed. // // Input, string TITLE, a title. // { # define INCX 5 int i; int i2hi; int i2lo; int j; int j2hi; int j2lo; cout << "\n"; cout << title << "\n"; // // Print the columns of the matrix, in strips of 5. // for ( j2lo = jlo; j2lo <= jhi; j2lo = j2lo + INCX ) { j2hi = j2lo + INCX - 1; j2hi = i4_min ( j2hi, n ); j2hi = i4_min ( j2hi, jhi ); cout << "\n"; cout << " Col: "; for ( j = j2lo; j <= j2hi; j++ ) { cout << setw(7) << j << " "; } cout << "\n"; cout << " Row\n"; cout << " ---\n"; // // Determine the range of the rows in this strip. // i2lo = i4_max ( ilo, 1 ); i2lo = i4_max ( i2lo, j2lo ); i2hi = i4_min ( ihi, n ); i2hi = i4_min ( i2hi, j2hi + ml ); for ( i = i2lo; i <= i2hi; i++ ) { cout << setw(5) << i << " "; // // Print out (up to) 5 entries in row I, that lie in the current strip. // for ( j = j2lo; j <= j2hi; j++ ) { if ( ml < i-j || 0 < j-i ) { cout << " "; } else { cout << setw(12) << a[i-j+(j-1)*(ml+1)] << " "; } } cout << "\n"; } } cout << "\n"; return; # undef INCX } //****************************************************************************80 double *r8blt_random ( int n, int ml, int &seed ) //****************************************************************************80 // // Purpose: // // R8BLT_RANDOM randomizes an R8BLT matrix. // // Discussion: // // The R8BLT storage format is appropriate for a banded lower triangular matrix. // The matrix is assumed to be zero below the ML-th subdiagonal. // The matrix is stored in an ML+1 by N array, in which the diagonal // appears in the first row, followed by successive subdiagonals. // Columns are preserved. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 12 October 2003 // // Author: // // John Burkardt // // Parameters: // // Input, int N, the number of columns of the matrix. // // Input, int ML, the lower bandwidth. // // Input/output, int &SEED, a seed for the random number generator. // // Output, double R8BLT_RANDOM[(ML+1)*N], the R8BLT matrix. // { double *a; int i; int j; int jlo; a = new double[(ml+1)*n]; for ( i = 0; i < n; i++ ) { jlo = i4_max ( 0, i - ml ); for ( j = jlo; j <= i; j++ ) { a[i-j+j*(ml+1)] = r8_uniform_01 ( seed ); } } // // The junk entries can be thought of as corresponding to // elements of a phantom portion of the matrix. // for ( i = n; i < n + ml; i++ ) { for ( j = i - ml; j < n; j++ ) { a[i-j+j*(ml+1)] = 0.0; } } return a; } //****************************************************************************80 double *r8blt_sl ( int n, int ml, double a[], double b[] ) //****************************************************************************80 // // Purpose: // // R8BLT_SL solves A*x=b, where A is an R8BLT matrix. // // Discussion: // // The R8BLT storage format is appropriate for a banded lower triangular matrix. // The matrix is assumed to be zero below the ML-th subdiagonal. // The matrix is stored in an ML+1 by N array, in which the diagonal // appears in the first row, followed by successive subdiagonals. // Columns are preserved. // // No factorization of the lower triangular matrix is required. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 05 October 2015 // // Author: // // John Burkardt // // Parameters: // // Input, int N, the order of the matrix. // // Input, int ML, the lower bandwidth. // // Input, double A[(ML+1)*N], the R8BLT matrix. // // Input, double B(N), the right hand side. // // Output, double R8BLT_SL[N], the solution vector. // { int i; int ihi; int j; double *x; x = new double[n]; for ( i = 0; i < n; i++ ) { x[i] = b[i]; } for ( j = 0; j < n; j++ ) { x[j] = x[j] / a[0+j*(ml+1)]; ihi = i4_min ( j + ml, n - 1 ); for ( i = j + 1; i <= ihi; i++ ) { x[i] = x[i] - a[i-j+j*(ml+1)] * x[j]; } } return x; } //****************************************************************************80 double *r8blt_slt ( int n, int ml, double a[], double b[] ) //****************************************************************************80 // // Purpose: // // R8BLT_SLT solves A'*x=b, where A is an R8BLT matrix. // // Discussion: // // The R8BLT storage format is appropriate for a banded lower triangular matrix. // The matrix is assumed to be zero below the ML-th subdiagonal. // The matrix is stored in an ML+1 by N array, in which the diagonal // appears in the first row, followed by successive subdiagonals. // Columns are preserved. // // No factorization of the lower triangular matrix is required. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 05 October 2015 // // Author: // // John Burkardt // // Parameters: // // Input, int N, the order of the matrix. // // Input, int ML, the lower bandwidth. // // Input, double A[(ML+1)*N], the R8BLT matrix. // // Input, double B(N), the right hand side. // // Output, double R8BLT_SLT[N], the solution vector. // { int i; int ilo; int j; double *x; x = new double[n]; for ( i = 0; i < n; i++ ) { x[i] = b[i]; } for ( j = n - 1; 0 <= j; j-- ) { x[j] = x[j] / a[0+j*(ml+1)]; ilo = i4_max ( j - ml, 0 ); for ( i = ilo; i <= j - 1; i++ ) { x[i] = x[i] - a[j-i+i*(ml+1)] * x[j]; } } return x; } //****************************************************************************80 double *r8blt_to_r8ge ( int n, int ml, double a[] ) //****************************************************************************80 // // Purpose: // // R8BLT_TO_R8GE copies an R8BLT matrix to an R8GE matrix. // // Discussion: // // The R8BLT storage format is used for a banded lower triangular matrix. // The matrix is assumed to be zero below the ML-th subdiagonal. // The matrix is stored in an ML+1 by N array, in which the diagonal // appears in the first row, followed by successive subdiagonals. // Columns are preserved. // // Example: // // N = 5, ML = 2 // // A11 0 0 0 0 // A21 A22 0 0 0 // A31 A32 A33 0 0 // 0 A42 A43 A44 0 // 0 0 A53 A54 A55 // --- --- // --- // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 28 March 2004 // // Author: // // John Burkardt // // Parameters: // // Input, int N, the order of the matrices. // N must be positive. // // Input, int ML, the lower bandwidth of A. // ML must be nonnegative, and no greater than N-1. // // Input, double A[(ML+1)*N], the R8BLT matrix. // // Output, double R8BLT_TO_R8GE[N*N], the R8GE matrix. // { double *b; int i; int j; b = new double[n*n]; for ( i = 1; i <= n; i++ ) { for ( j = 1; j <= n; j++ ) { if ( j <= i && i <= j + ml ) { b[i-1+(j-1)*n] = a[i-j+(j-1)*(ml+1)]; } else { b[i-1+(j-1)*n] = 0.0; } } } return b; } //****************************************************************************80 double *r8blt_zeros ( int n, int ml ) //****************************************************************************80 // // Purpose: // // R8BLT_ZEROS zeros an R8BLT matrix. // // Discussion: // // The R8BLT storage format is appropriate for a banded lower triangular matrix. // The matrix is assumed to be zero below the ML-th subdiagonal. // The matrix is stored in an ML+1 by N array, in which the diagonal // appears in the first row, followed by successive subdiagonals. // Columns are preserved. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 15 September 2003 // // Author: // // John Burkardt // // Parameters: // // Input, int N, the number of columns of the matrix. // // Input, int ML, the lower bandwidth. // // Output, double R8BLT_ZERO[(ML+1)*N], the R8BLT matrix. // { double *a; int i; int j; a = new double[(ml+1)*n]; for ( j = 0; j < n; j++ ) { for ( i = 0; i < ml+1; i++ ) { a[i+j*(ml+1)] = 0.0; } } return a; } //****************************************************************************80 void r8ge_print ( int m, int n, double a[], string title ) //****************************************************************************80 // // Purpose: // // R8GE_PRINT prints an R8GE matrix. // // Discussion: // // The R8GE storage format is used for a "general" M by N matrix. // A physical storage space is made for each logical entry. The two // dimensional logical array is mapped to a vector, in which storage is // by columns. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 06 April 2006 // // Author: // // John Burkardt // // Parameters: // // Input, int M, the number of rows of the matrix. // M must be positive. // // Input, int N, the number of columns of the matrix. // N must be positive. // // Input, double A[M*N], the R8GE matrix. // // Input, string TITLE, a title. // { r8ge_print_some ( m, n, a, 1, 1, m, n, title ); return; } //****************************************************************************80 void r8ge_print_some ( int m, int n, double a[], int ilo, int jlo, int ihi, int jhi, string title ) //****************************************************************************80 // // Purpose: // // R8GE_PRINT_SOME prints some of an R8GE matrix. // // Discussion: // // The R8GE storage format is used for a "general" M by N matrix. // A physical storage space is made for each logical entry. The two // dimensional logical array is mapped to a vector, in which storage is // by columns. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 06 April 2006 // // Author: // // John Burkardt // // Parameters: // // Input, int M, the number of rows of the matrix. // M must be positive. // // Input, int N, the number of columns of the matrix. // N must be positive. // // Input, double A[M*N], the R8GE matrix. // // Input, int ILO, JLO, IHI, JHI, designate the first row and // column, and the last row and column to be printed. // // Input, string TITLE, a title. // { # define INCX 5 int i; int i2hi; int i2lo; int j; int j2hi; int j2lo; cout << "\n"; cout << title << "\n"; // // Print the columns of the matrix, in strips of 5. // for ( j2lo = jlo; j2lo <= jhi; j2lo = j2lo + INCX ) { j2hi = j2lo + INCX - 1; j2hi = i4_min ( j2hi, n ); j2hi = i4_min ( j2hi, jhi ); cout << "\n"; // // For each column J in the current range... // // Write the header. // cout << " Col: "; for ( j = j2lo; j <= j2hi; j++ ) { cout << setw(7) << j << " "; } cout << "\n"; cout << " Row\n"; cout << " ---\n"; // // Determine the range of the rows in this strip. // i2lo = i4_max ( ilo, 1 ); i2hi = i4_min ( ihi, m ); for ( i = i2lo; i <= i2hi; i++ ) { // // Print out (up to) 5 entries in row I, that lie in the current strip. // cout << setw(5) << i << " "; for ( j = j2lo; j <= j2hi; j++ ) { cout << setw(12) << a[i-1+(j-1)*m] << " "; } cout << "\n"; } } return; # undef INCX } //****************************************************************************80 double *r8vec_indicator1_new ( int n ) //****************************************************************************80 // // Purpose: // // R8VEC_INDICATOR1_NEW sets an R8VEC to the indicator1 vector {1,2,3...}. // // Discussion: // // An R8VEC is a vector of R8's. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 20 September 2005 // // Author: // // John Burkardt // // Parameters: // // Input, int N, the number of elements of A. // // Output, double R8VEC_INDICATOR1_NEW[N], the array to be initialized. // { double *a; int i; a = new double[n]; for ( i = 0; i <= n-1; i++ ) { a[i] = ( double ) ( i + 1 ); } return a; } //****************************************************************************80 void r8vec_print ( int n, double a[], string title ) //****************************************************************************80 // // Purpose: // // R8VEC_PRINT prints an R8VEC. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 14 November 2003 // // Author: // // John Burkardt // // Parameters: // // Input, int N, the number of components of the vector. // // Input, double A[N], the vector to be printed. // // Input, string TITLE, a title. // { int i; cout << "\n"; cout << title << "\n"; cout << "\n"; for ( i = 0; i < n; i++ ) { cout << setw(6) << i + 1 << " " << setw(14) << a[i] << "\n"; } return; } //****************************************************************************80 double *r8vec_uniform_01_new ( int n, int &seed ) //****************************************************************************80 // // Purpose: // // R8VEC_UNIFORM_01_NEW returns a new unit pseudorandom R8VEC. // // Discussion: // // This routine implements the recursion // // seed = ( 16807 * seed ) mod ( 2^31 - 1 ) // u = seed / ( 2^31 - 1 ) // // The integer arithmetic never requires more than 32 bits, // including a sign bit. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 19 August 2004 // // 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 N, the number of entries in the vector. // // Input/output, int &SEED, a seed for the random number generator. // // Output, double R8VEC_UNIFORM_01_NEW[N], the vector of pseudorandom values. // { int i; const int i4_huge = 2147483647; int k; double *r; if ( seed == 0 ) { cerr << "\n"; cerr << "R8VEC_UNIFORM_01_NEW - Fatal error!\n"; cerr << " Input value of SEED = 0.\n"; exit ( 1 ); } r = new double[n]; for ( i = 0; i < n; i++ ) { k = seed / 127773; seed = 16807 * ( seed - k * 127773 ) - k * 2836; if ( seed < 0 ) { seed = seed + i4_huge; } r[i] = ( double ) ( seed ) * 4.656612875E-10; } return r; } //****************************************************************************80 double *r8vec_zeros_new ( int n ) //****************************************************************************80 // // Purpose: // // R8VEC_ZEROS_NEW creates and zeroes an R8VEC. // // Discussion: // // An R8VEC is a vector of R8's. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 10 July 2008 // // Author: // // John Burkardt // // Parameters: // // Input, int N, the number of entries in the vector. // // Output, double R8VEC_ZEROS_NEW[N], a vector of zeroes. // { double *a; int i; a = new double[n]; for ( i = 0; i < n; i++ ) { a[i] = 0.0; } return a; } //****************************************************************************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; std::time_t now; now = std::time ( NULL ); tm_ptr = std::localtime ( &now ); std::strftime ( time_buffer, TIME_SIZE, "%d %B %Y %I:%M:%S %p", tm_ptr ); std::cout << time_buffer << "\n"; return; # undef TIME_SIZE }