# include # include # include # include # include using namespace std; # include "line_grid.hpp" //****************************************************************************80 double *line_grid ( int n, double a, double b, int c ) //****************************************************************************80 // // Purpose: // // LINE_GRID: grid points over the interior of a line segment in 1D. // // Discussion: // // In 1D, a grid is created using N points. // // Over the interval [A,B], we have 5 choices for grid centering: // 1: 0, 1/3, 2/3, 1 // 2: 1/5, 2/5, 3/5, 4/5 // 3: 0, 1/4, 2/4, 3/4 // 4: 1/4, 2/4, 3/4, 1 // 5: 1/8, 3/8, 5/8, 7/8 // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 31 August 2014 // // Author: // // John Burkardt // // Parameters: // // Input, int N, the number of points. // // Input, double A, B, the endpoints. // // Input, int C, the grid centering. // 1 <= C <= 5. // // Output, double LINE_GRID[N], the points. // { int j; double *x; x = new double[n]; // // Create the 1D grids in each dimension. // for ( j = 0; j < n; j++ ) { if ( c == 1 ) { if ( n == 1 ) { x[j] = 0.5 * ( a + b ); } else { x[j] = ( ( double ) ( n - j - 1 ) * a + ( double ) ( j ) * b ) / ( double ) ( n - 1 ); } } else if ( c == 2 ) { x[j] = ( ( double ) ( n - j ) * a + ( double ) ( j + 1 ) * b ) / ( double ) ( n + 1 ); } else if ( c == 3 ) { x[j] = ( ( double ) ( n - j ) * a + ( double ) ( j - 2 ) * b ) / ( double ) ( n ); } else if ( c == 4 ) { x[j] = ( ( double ) ( n - j - 1 ) * a + ( double ) ( j + 1 ) * b ) / ( double ) ( n ); } else if ( c == 5 ) { x[j] = ( ( double ) ( 2 * n - 2 * j - 1 ) * a + ( double ) ( 2 * j + 1 ) * b ) / ( double ) ( 2 * n ); } } return x; } //****************************************************************************80 void r8vec_print ( int n, double a[], string title ) //****************************************************************************80 // // Purpose: // // R8VEC_PRINT prints an R8VEC. // // Discussion: // // An R8VEC is a vector of R8's. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 16 August 2004 // // 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(8) << i << ": " << setw(14) << a[i] << "\n"; } return; } //****************************************************************************80 void timestamp ( ) //****************************************************************************80 // // Purpose: // // TIMESTAMP prints the current YMDHMS date as a time stamp. // // Example: // // 31 May 2001 09:45:54 AM // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 08 July 2009 // // Author: // // John Burkardt // // Parameters: // // None // { # define TIME_SIZE 40 static char time_buffer[TIME_SIZE]; const struct std::tm *tm_ptr; 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 }