--enable-epetraext-hdf5
. The simplest of the input function is EpetraExt::MatlabFileToCrsMatrix. This function requires only a valid ASCII file containing 1 or more lines where each row is of the form: (row_index, col_index, value) and a valid Epetra_Comm object. The matrix domain and range maps are assumed to have a size of the maximum row and column index present in the file, respectively, and will be constructed as uniform distributed maps. The row map will be identical to the range map and the column map will be determined by which columns are present for the rows on a given processor.
The simplest output functions are EpetraExt::RowMatrixToMatlabFile and EpetraExt:OperatorToMatlabFile, which write out any Epetra_RowMatrix or Epetra_Operator object, respectively. Epetra_Operator coefficients are generated by multiplying the operator with the canonical vectors, several at a time for performance reasons.
The I/O function are summarized below:
The following example (from Trilinos/packages/aztecoo/example/AztecOO_Matlab_Input) shows an interesting use of these classes, illustrating how to use these classes in conjunction with AztecOO to write out the coefficients of the inverse of a matrix:
/*@HEADER // *********************************************************************** // // AztecOO: An Object-Oriented Aztec Linear Solver Package // Copyright (2002) Sandia Corporation // // Under terms of Contract DE-AC04-94AL85000, there is a non-exclusive // license for use of this work by or on behalf of the U.S. Government. // // This library is free software; you can redistribute it and/or modify // it under the terms of the GNU Lesser General Public License as // published by the Free Software Foundation; either version 2.1 of the // License, or (at your option) any later version. // // This library is distributed in the hope that it will be useful, but // WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU // Lesser General Public License for more details. // // You should have received a copy of the GNU Lesser General Public // License along with this library; if not, write to the Free Software // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 // USA // Questions? Contact Michael A. Heroux (maherou@sandia.gov) // // *********************************************************************** //@HEADER */ #include "AztecOO_config.h" #ifdef HAVE_MPI #include "mpi.h" #include "Epetra_MpiComm.h" #else #include "Epetra_SerialComm.h" #endif #include "Epetra_Map.h" #include "Epetra_Vector.h" #include "Epetra_CrsMatrix.h" #include "EpetraExt_OperatorOut.h" #include "EpetraExt_CrsMatrixIn.h" #include "AztecOO_Operator.h" #include "Epetra_InvOperator.h" #include <string> // prototypes int checkValues( double x, double y, string message = "", bool verbose = false) { if (fabs((x-y)/x) > 0.01) { return(1); if (verbose) cout << "********** " << message << " check failed.********** " << endl; } else { if (verbose) cout << message << " check OK." << endl; return(0); } } int main(int argc, char *argv[]) { #ifdef HAVE_MPI MPI_Init(&argc,&argv); Epetra_MpiComm comm (MPI_COMM_WORLD); #else Epetra_SerialComm comm; #endif int MyPID = comm.MyPID(); bool verbose = false; bool verbose1 = false; // Check if we should print results to standard out if (argc > 1) { if ((argv[1][0] == '-') && (argv[1][1] == 'v')) { verbose1 = true; if (MyPID==0) verbose = true; } } if (verbose1) cout << comm << endl; // Uncomment the next three lines to debug in mpi mode //int tmp; //if (MyPID==0) cin >> tmp; //comm.Barrier(); Epetra_CrsMatrix * A; EPETRA_CHK_ERR(EpetraExt::MatlabFileToCrsMatrix("A.dat", comm, A)); Epetra_Vector x(A->OperatorDomainMap()); Epetra_Vector b(A->OperatorRangeMap()); x.Random(); A->Apply(x,b); // Generate RHS from x Epetra_Vector xx(x); // Copy x to xx for later use Epetra_LinearProblem problem(A, &x, &b); // Construct a solver object for this problem AztecOO solver(problem); solver.SetAztecOption(AZ_precond, AZ_none); if (!verbose1) solver.SetAztecOption(AZ_output, AZ_none); solver.SetAztecOption(AZ_kspace, A->NumGlobalRows()); AztecOO_Operator AOpInv(&solver, A->NumGlobalRows()); Epetra_InvOperator AInvOp(&AOpInv); EPETRA_CHK_ERR(EpetraExt::OperatorToMatlabFile("Ainv.dat", AInvOp)); comm.Barrier(); Epetra_CrsMatrix * AInv; EPETRA_CHK_ERR(EpetraExt::MatlabFileToCrsMatrix("Ainv.dat", comm, AInv)); EPETRA_CHK_ERR(AInv->Apply(b,x)); EPETRA_CHK_ERR(x.Update(1.0, xx, -1.0)); double residual = 0.0; EPETRA_CHK_ERR(x.Norm2(&residual)); if (verbose) cout << "Norm of difference between computed x and exact x = " << residual << endl; int ierr = checkValues(residual,0.0,"Norm of difference between computed A1x1 and A1x1 from file", verbose); delete A; delete AInv; #ifdef HAVE_MPI MPI_Finalize() ; #endif return(ierr); }
EpetraExt::ModelEvaluator
provides an Epetra-specific interface to nonlinear models for use by equation solvers all the way up to optimization.