# include # include # include # include using namespace std; # include "umfpack.h" int main ( ); void timestamp ( ); //****************************************************************************80 int main ( ) //****************************************************************************80 // // Purpose: // // MAIN is the main program for UMFPACK_SIMPLE. // // Discussion: // // This program uses UMFPACK to solve the 5x5 linear system A*X=B: // // 2 3 0 0 0 1.0 8.0 // 3 0 4 0 6 2.0 45.0 // A = 0 -1 -3 2 0 X = 3.0 B = -3.0 // 0 0 1 0 0 4.0 3.0 // 0 4 2 0 1 5.0 10.0 // // The matrix contains 12 nonzero values. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 29 January 2014 // // Reference: // // Timothy Davis, // UMFPACK User Guide, // Version 5.6.2, 25 April 2013 // http://suitesparse.com // { # define N 5 # define NCC 12 int Ai[NCC] = { 0, 1, 0, 2, 4, 1, 2, 3, 4, 2, 1, 4 }; int Ap[N+1] = { 0, 2, 5, 9, 10, 12 }; double Ax[NCC] = { 2.0, 3.0, 3.0, -1.0, 4.0, 4.0, -3.0, 1.0, 2.0, 2.0, 6.0, 1.0 }; double b[N] = { 8.0, 45.0, -3.0, 3.0, 19.0 }; int i; int n = 5; double *null = ( double * ) NULL; void *Numeric; int status; void *Symbolic; double x[N]; timestamp ( ); cout << "\n"; cout << "UMFPACK_SIMPLE:\n"; cout << " C++ version\n"; cout << " Use UMFPACK to solve the sparse linear system A*x=b.\n"; // // Carry out the symbolic factorization. // status = umfpack_di_symbolic ( n, n, Ap, Ai, Ax, &Symbolic, null, null ); // // Use the symbolic factorization to carry out the numeric factorization. // status = umfpack_di_numeric (Ap, Ai, Ax, Symbolic, &Numeric, null, null ); // // Free the memory associated with the symbolic factorization. // umfpack_di_free_symbolic ( &Symbolic ); // // Solve the linear system. // status = umfpack_di_solve ( UMFPACK_A, Ap, Ai, Ax, x, b, Numeric, null, null ); // // Free the memory associated with the numeric factorization. // umfpack_di_free_numeric ( &Numeric ); // // Print the solution. // cout << "\n"; cout << " Computed solution:\n"; cout << "\n"; for ( i = 0; i < n; i++ ) { cout << " x[" << i << "] = " << x[i] << "\n"; } // // Terminate. // cout << "\n"; cout << "UMFPACK_SIMPLE:\n"; cout << " Normal end of execution.\n"; cout << "\n"; timestamp ( ); return 0; # undef N # undef NCC } //****************************************************************************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 }