# include # include # include # include # include using namespace std; # include "r8ncf.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 int *i4vec_zeros_new ( int n ) //****************************************************************************80 // // Purpose: // // I4VEC_ZEROS_NEW creates and zeroes an I4VEC. // // Discussion: // // An I4VEC is a vector of I4's. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 11 July 2008 // // Author: // // John Burkardt // // Parameters: // // Input, int N, the number of entries in the vector. // // Output, int I4VEC_ZEROS_NEW[N], a vector of zeroes. // { int *a; int i; a = new int[n]; for ( i = 0; i < n; i++ ) { a[i] = 0; } return a; } //****************************************************************************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 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 *r8ncf_dif2 ( int m, int n, int nz_num, int rowcol[] ) //****************************************************************************80 // // Purpose: // // R8NCF_DIF2 sets up an R8NCF second difference matrix. // // Discussion: // // The R8NCF storage format stores NZ_NUM, the number of nonzeros, // a real array containing the nonzero values, a 2 by NZ_NUM integer // array storing the row and column of each nonzero entry. // // The R8NCF format is used by NSPCG. NSPCG requires that the information // for the diagonal entries of the matrix must come first. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 20 July 2016 // // Author: // // John Burkardt // // Parameters: // // Input, int M, N, the number of rows and columns in // the matrix. // // Input, int NZ_NUM, the number of nonzero entries. // // Input, int ROWCOL[2,NZ_NUM], the coordinates of // the nonzero entries. // // Output, double A[NZ_NUM], the matrix. // { double *a; int i; int j; int k; a = r8vec_zeros_new ( nz_num ); for ( k = 0; k < nz_num; k++ ) { i = rowcol[0+k*2]; j = rowcol[1+k*2]; if ( j == i - 1 ) { a[k] = -1.0; } else if ( j == i ) { a[k] = 2.0; } else if ( j == i + 1 ) { a[k] = -1.0; } } return a; } //****************************************************************************80 int r8ncf_dif2_nz_num ( int m, int n ) //****************************************************************************80 // // Purpose: // // R8NCF_DIF2_NZ_NUM counts nonzeros in an R8NCF second difference matrix. // // Discussion: // // The R8NCF storage format stores NZ_NUM, the number of nonzeros, // a real array containing the nonzero values, a 2 by NZ_NUM integer // array storing the row and column of each nonzero entry. // // The R8NCF format is used by NSPCG. NSPCG requires that the information // for the diagonal entries of the matrix must come first. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 20 July 2016 // // Author: // // John Burkardt // // Parameters: // // Input, int M, N, the number of rows and columns in // the matrix. // // Output, int NZ_NUM, the number of nonzero entries. // { int nz_num; if ( m < n ) { nz_num = 3 * m - 1; } else if ( m == n ) { nz_num = 3 * n - 2; } else { nz_num = 3 * n - 1; } return nz_num; } //****************************************************************************80 int *r8ncf_dif2_rowcol ( int m, int n, int nz_num ) //****************************************************************************80 // // Purpose: // // R8NCF_DIF2_ROWCOL sets indexing for an R8NCF second difference matrix. // // Discussion: // // The R8NCF storage format stores NZ_NUM, the number of nonzeros, // a real array containing the nonzero values, a 2 by NZ_NUM integer // array storing the row and column of each nonzero entry. // // The R8NCF format is used by NSPCG. NSPCG requires that the information // for the diagonal entries of the matrix must come first. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 20 July 2016 // // Author: // // John Burkardt // // Parameters: // // Input, int M, N, the number of rows and columns in // the matrix. // // Input, int NZ_NUM, the number of nonzero entries. // // Output, int ROWCOL[2*NZ_NUM], the coordinates of // the nonzero entries. // { int i; int j; int k; int *rowcol; rowcol = i4vec_zeros_new ( 2 * nz_num ); k = 0; for ( i = 0; i < m; i++ ) { j = i - 1; if ( 0 <= j && j < n ) { rowcol[0+k*2] = i; rowcol[1+k*2] = j; k = k + 1; } j = i; if ( j < n ) { rowcol[0+k*2] = i; rowcol[1+k*2] = j; k = k + 1; } j = i + 1; if ( j < n ) { rowcol[0+k*2] = i; rowcol[1+k*2] = j; k = k + 1; } } return rowcol; } //****************************************************************************80 double *r8ncf_indicator ( int m, int n, int nz_num, int rowcol[] ) //****************************************************************************80 // // Purpose: // // R8NCF_INDICATOR sets up an R8NCF indicator matrix. // // Discussion: // // The R8NCF storage format stores NZ_NUM, the number of nonzeros, // a real array containing the nonzero values, a 2 by NZ_NUM integer // array storing the row and column of each nonzero entry. // // The R8NCF format is used by NSPCG. NSPCG requires that the information // for the diagonal entries of the matrix must come first. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 02 August 2006 // // Author: // // John Burkardt // // Parameters: // // Input, int M, N, the number of rows and columns in the matrix. // // Input, int NZ_NUM, the number of nonzero entries. // // Input, int ROWCOL[2*NZ_NUM], the coordinates of the nonzero entries. // // Output, double A[NZ_NUM], the indicator matrix. // { double *a; int fac; int i; int j; int k; a = r8vec_zeros_new ( nz_num ); fac = i4_power ( 10, i4_log_10 ( n ) + 1 ); for ( k = 0; k < nz_num; k++ ) { i = rowcol[0+k*2]; j = rowcol[1+k*2]; a[k] = ( double ) ( fac * ( i + 1 ) + ( j + 1 ) ); } return a; } //****************************************************************************80 double *r8ncf_mtv ( int m, int n, int nz_num, int rowcol[], double a[], double x[] ) //****************************************************************************80 // // Purpose: // // R8NCF_MTV multiplies an R8VEC times an R8NCF matrix. // // Discussion: // // The R8NCF storage format stores NZ_NUM, the number of nonzeros, // a real array containing the nonzero values, a 2 by NZ_NUM integer // array storing the row and column of each nonzero entry. // // The R8NCF format is used by NSPCG. NSPCG requires that the information // for the diagonal entries of the matrix must come first. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 21 July 2016 // // Author: // // John Burkardt // // Parameters: // // Input, int M, N, the order of the matrix. // // Input, int NZ_NUM, the number of nonzero elements in // the matrix. // // Input, int ROWCOL[2*NZ_NUM], the row and column // indices of the nonzero elements. // // Input, double A[NZ_NUM], the nonzero elements of the matrix. // // Input, double X[M], the vector to be multiplied by A'. // // Output, double R8NCF_MTV[N], the product A' * x. // { double *b; int i; int j; int k; b = r8vec_zeros_new ( n ); for ( k = 0; k < nz_num; k++ ) { i = rowcol[0+k*2]; j = rowcol[1+k*2]; b[j] = b[j] + a[k] * x[i]; } return b; } //****************************************************************************80 double *r8ncf_mv ( int m, int n, int nz_num, int rowcol[], double a[], double x[] ) //****************************************************************************80 // // Purpose: // // R8NCF_MV multiplies an R8NCF matrix by an R8VEC. // // Discussion: // // The R8NCF storage format stores NZ_NUM, the number of nonzeros, // a real array containing the nonzero values, a 2 by NZ_NUM integer // array storing the row and column of each nonzero entry. // // The R8NCF format is used by NSPCG. NSPCG requires that the information // for the diagonal entries of the matrix must come first. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 21 July 2016 // // Author: // // John Burkardt // // Parameters: // // Input, int M, N, the order of the matrix. // // Input, int NZ_NUM, the number of nonzero elements in // the matrix. // // Input, int ROWCOL[2*NZ_NUM], the row and column // indices of the nonzero elements. // // Input, double A[NZ_NUM], the nonzero elements of the matrix. // // Input, double X[N], the vector to be multiplied by A. // // Output, double R8NCF_MV[M], the product A * x. // { double *b; int i; int j; int k; b = r8vec_zeros_new ( m ); for ( k = 0; k < nz_num; k++ ) { i = rowcol[0+k*2]; j = rowcol[1+k*2]; b[i] = b[i] + a[k] * x[j]; } return b; } //****************************************************************************80 void r8ncf_print ( int m, int n, int nz_num, int rowcol[], double a[], string title ) //****************************************************************************80 // // Purpose: // // R8NCF_PRINT prints an R8NCF matrix. // // Discussion: // // The R8NCF storage format stores NZ_NUM, the number of nonzeros, // a real array containing the nonzero values, a 2 by NZ_NUM integer // array storing the row and column of each nonzero entry. // // The R8NCF format is used by NSPCG. NSPCG requires that the information // for the diagonal entries of the matrix must come first. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 02 August 2006 // // Author: // // John Burkardt // // Parameters: // // Input, int M, N, the number of rows and columns of the matrix. // // Input, int NZ_NUM, the number of nonzero elements in the matrix. // // Input, int ROWCOL[2*NZ_NUM], the row and column indices // of the nonzero elements. // // Input, double A[NZ_NUM], the nonzero elements of the matrix. // // Input, string TITLE, a title. // { r8ncf_print_some ( m, n, nz_num, rowcol, a, 0, 0, m - 1, n - 1, title ); return; } //****************************************************************************80 void r8ncf_print_some ( int m, int n, int nz_num, int rowcol[], double a[], int ilo, int jlo, int ihi, int jhi, string title ) //****************************************************************************80 // // Purpose: // // R8NCF_PRINT_SOME prints some of an R8NCF matrix. // // Discussion: // // The R8NCF storage format stores NZ_NUM, the number of nonzeros, // a real array containing the nonzero values, a 2 by NZ_NUM integer // array storing the row and column of each nonzero entry. // // The R8NCF format is used by NSPCG. NSPCG requires that the information // for the diagonal entries of the matrix must come first. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 20 July 2016 // // Author: // // John Burkardt // // Parameters: // // Input, int M, N, the number of rows and columns of the matrix. // // Input, int NZ_NUM, the number of nonzero elements in the matrix. // // Input, int ROWCOL[2*NZ_NUM], the row and column indices // of the nonzero elements. // // Input, double A[NZ_NUM], the nonzero elements of the matrix. // // Input, int ILO, JLO, IHI, JHI, the first row and // column, and the last row and column to be printed. // // Input, string TITLE, a title. // { # define INCX 5 double aij; int i; int i2hi; int i2lo; int j; int j2hi; int j2lo; int k; 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 - 1 ); 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, 0 ); i2hi = i4_min ( ihi, m - 1 ); for ( i = i2lo; i <= i2hi; i++ ) { cout << setw(5) << i; for ( j = j2lo; j <= j2hi; j++ ) { aij = 0.0; for ( k = 0; k < nz_num; k++ ) { if ( rowcol[0+k*2] == i && rowcol[1+k*2] == j ) { aij = a[k]; break; } } cout << " " << setw(12) << aij; } cout << "\n"; } } return; # undef INCX } //****************************************************************************80 double *r8ncf_random ( int m, int n, int nz_num, int rowcol[], int &seed ) //****************************************************************************80 // // Purpose: // // R8NCF_RANDOM randomizes an R8NCF matrix. // // Discussion: // // The R8NCF storage format stores NZ_NUM, the number of nonzeros, // a real array containing the nonzero values, a 2 by NZ_NUM integer // array storing the row and column of each nonzero entry. // // The R8NCF format is used by NSPCG. NSPCG requires that the information // for the diagonal entries of the matrix must come first. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 21 July 2016 // // Author: // // John Burkardt // // Parameters: // // Input, int M, N, the number of rows and columns in // the matrix. // // Input, int NZ_NUM, the number of nonzero entries. // // Input, int ROWCOL[2*NZ_NUM], the coordinates of // the nonzero entries. // // Input/output, int &SEED, a seed for the random // number generator. // // Output, double R8NCF_RANDOM[NZ_NUM], the indicator matrix. // { double *a; int k; a = r8vec_zeros_new ( nz_num ); for ( k = 0; k < nz_num; k++ ) { a[k] = r8_uniform_01 ( seed ); } return a; } //****************************************************************************80 double *r8ncf_to_r8ge ( int m, int n, int nz_num, int rowcol[], double a[] ) //****************************************************************************80 // // Purpose: // // R8NCF_TO_R8GE converts an R8NCF matrix to R8GE format. // // Discussion: // // The R8NCF storage format stores NZ_NUM, the number of nonzeros, // a real array containing the nonzero values, a 2 by NZ_NUM integer // array storing the row and column of each nonzero entry. // // The R8NCF format is used by NSPCG. NSPCG requires that the information // for the diagonal entries of the matrix must come first. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 21 July 2016 // // Author: // // John Burkardt // // Parameters: // // Input, int M, N, the number of rows and columns in // the matrix. // // Input, int NZ_NUM, the number of nonzero entries. // // Input, int ROWCOL[2*NZ_NUM], the coordinates of // the nonzero entries. // // Input, double A[NZ_NUM], the matrix. // // Output, double R8NCF_TO_R8GE[M*N], the R8GE matrix. // { double *a_r8ge; int i; int j; int k; a_r8ge = r8vec_zeros_new ( m * n ); for ( k = 0; k < nz_num; k++ ) { i = rowcol[0+k*2]; j = rowcol[1+k*2]; a_r8ge[i+j*m] = a_r8ge[i+j*m] + a[k]; } return a_r8ge; } //****************************************************************************80 double *r8ncf_zeros ( int m, int n, int nz_num, int rowcol[] ) //****************************************************************************80 // // Purpose: // // R8NCF_ZEROS zeros an R8NCF matrix. // // Discussion: // // The R8NCF storage format stores NZ_NUM, the number of nonzeros, // a real array containing the nonzero values, a 2 by NZ_NUM integer // array storing the row and column of each nonzero entry. // // The R8NCF format is used by NSPCG. NSPCG requires that the information // for the diagonal entries of the matrix must come first. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 18 August 2015 // // Author: // // John Burkardt // // Parameters: // // Input, int M, N, the number of rows and columns in the matrix. // // Input, int NZ_NUM, the number of nonzero entries. // // Input, int ROWCOL[2*NZ_NUM], the coordinates of the nonzero entries. // // Output, double R8NCF_ZEROS[NZ_NUM], the matrix. // { double *a; a = r8vec_zeros_new ( nz_num ); return a; } //****************************************************************************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 = r8vec_zeros_new ( 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_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 }