test/SerialDense_LL/cxx_main.cpp

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#include "Epetra_Map.h"
#include "Epetra_Time.h"
#include "Epetra_SerialDenseMatrix.h"
#include "Epetra_SerialDenseVector.h"
#include "Epetra_SerialDenseSolver.h"
#ifdef EPETRA_MPI
#include "Epetra_MpiComm.h"
#include <mpi.h>
#endif
#include "Epetra_SerialComm.h"
#include "../epetra_test_err.h"
#include "Epetra_Version.h"

// prototypes

int check(Epetra_SerialDenseSolver & solver, double * A1, int LDA,
    int N1, int NRHS1, double OneNorm1,
    double * B1, int LDB1,
    double * X1, int LDX1,
    bool Transpose, bool verbose);

void GenerateHilbert(double *A, int LDA, int N);

bool Residual( int N, int NRHS, double * A, int LDA, bool Transpose,
         double * X, int LDX, double * B, int LDB, double * resid);

int matrixCpyCtr(bool verbose, bool debug);
int matrixAssignment(bool verbose, bool debug);
void printHeading(const char* heading);
double* getRandArray(int length);
void printMat(const char* name, Epetra_SerialDenseMatrix& matrix);
void printArray(double* array, int length);
bool identicalSignatures(Epetra_SerialDenseMatrix& a, Epetra_SerialDenseMatrix& b, bool testLDA = true);
bool seperateData(Epetra_SerialDenseMatrix& a, Epetra_SerialDenseMatrix& b);


int main(int argc, char *argv[])
{
  int ierr = 0, i, j, k;
  bool debug = false;

#ifdef EPETRA_MPI
  MPI_Init(&argc,&argv);
  Epetra_MpiComm Comm( MPI_COMM_WORLD );
#else
  Epetra_SerialComm Comm;
#endif

  bool verbose = false;

  // Check if we should print results to standard out
  if (argc>1) if (argv[1][0]=='-' && argv[1][1]=='v') verbose = true;

  if (verbose && Comm.MyPID()==0)
    cout << Epetra_Version() << endl << endl;

  int rank = Comm.MyPID();
  //  char tmp;
  //  if (rank==0) cout << "Press any key to continue..."<< endl;
  //  if (rank==0) cin >> tmp;
  //  Comm.Barrier();

  Comm.SetTracebackMode(0); // This should shut down any error traceback reporting
  if (verbose) cout << Comm <<endl;

  //  bool verbose1 = verbose;

  // Redefine verbose to only print on PE 0
  if (verbose && rank!=0) verbose = false;
  
  int N = 20;
  int NRHS = 4;
  double * A = new double[N*N];
  double * A1 = new double[N*N];
  double * X = new double[(N+1)*NRHS];
  double * X1 = new double[(N+1)*NRHS];
  int LDX = N+1;
  int LDX1 = N+1;
  double * B = new double[N*NRHS];
  double * B1 = new double[N*NRHS];
  int LDB = N;
  int LDB1 = N;

  int LDA = N;
  int LDA1 = LDA;
  double OneNorm1;
  bool Transpose = false;

  Epetra_SerialDenseSolver solver;
  Epetra_SerialDenseMatrix * Matrix;
  for (int kk=0; kk<2; kk++) {
    for (i=1; i<=N; i++) {
      GenerateHilbert(A, LDA, i);
      OneNorm1 = 0.0;
      for (j=1; j<=i; j++) OneNorm1 += 1.0/((double) j); // 1-Norm = 1 + 1/2 + ...+1/n

      if (kk==0) {
  Matrix = new Epetra_SerialDenseMatrix(View, A, LDA, i, i);
  LDA1 = LDA;
      }
      else {
  Matrix = new Epetra_SerialDenseMatrix(Copy, A, LDA, i, i);
  LDA1 = i;
      }

      GenerateHilbert(A1, LDA1, i);
  
      if (kk==1) {
  solver.FactorWithEquilibration(true);
  solver.SolveWithTranspose(true);
  Transpose = true;
  solver.SolveToRefinedSolution(true);
      }

      for (k=0; k<NRHS; k++)
  for (j=0; j<i; j++) {
    B[j+k*LDB] = 1.0/((double) (k+3)*(j+3));
    B1[j+k*LDB1] = B[j+k*LDB1];
  }
      Epetra_SerialDenseMatrix Epetra_B(View, B, LDB, i, NRHS);
      Epetra_SerialDenseMatrix Epetra_X(View, X, LDX, i, NRHS);

      solver.SetMatrix(*Matrix);
      solver.SetVectors(Epetra_X, Epetra_B);

      ierr = check(solver, A1, LDA1,  i, NRHS, OneNorm1, B1, LDB1,  X1, LDX1, Transpose, verbose);
      assert (ierr>-1);
      delete Matrix;
      if (ierr!=0) {
  if (verbose) cout << "Factorization failed due to bad conditioning.  This is normal if RCOND is small."
        << endl;
  break;
      }
    }
  }

  delete [] A;
  delete [] A1;
  delete [] X;
  delete [] X1;
  delete [] B;
  delete [] B1;

  // Now test norms and scaling functions

  Epetra_SerialDenseMatrix D;
  double ScalarA = 2.0;

  int DM = 10;
  int DN = 8;
  D.Shape(DM, DN);
  for (j=0; j<DN; j++)
    for (i=0; i<DM; i++) D[j][i] = (double) (1+i+j*DM) ;

  //cout << D << endl;

  double NormInfD_ref = (double)(DM*(DN*(DN+1))/2);
  double NormOneD_ref = (double)((DM*DN*(DM*DN+1))/2 - (DM*(DN-1)*(DM*(DN-1)+1))/2 );

  double NormInfD = D.NormInf();
  double NormOneD = D.NormOne();

  if (verbose) {
    cout << " *** Before scaling *** " << endl
   << " Computed one-norm of test matrix = " << NormOneD << endl
   << " Expected one-norm                = " << NormOneD_ref << endl
   << " Computed inf-norm of test matrix = " << NormInfD << endl
   << " Expected inf-norm                = " << NormInfD_ref << endl;
  }
  D.Scale(ScalarA); // Scale entire D matrix by this value
  NormInfD = D.NormInf();
  NormOneD = D.NormOne();
  if (verbose) {
    cout << " *** After scaling *** " << endl
   << " Computed one-norm of test matrix = " << NormOneD << endl
   << " Expected one-norm                = " << NormOneD_ref*ScalarA << endl
   << " Computed inf-norm of test matrix = " << NormInfD << endl
   << " Expected inf-norm                = " << NormInfD_ref*ScalarA << endl;
  }


  // Now test that A.Multiply(false, x, y) produces the same result
  // as y.Multiply('N','N', 1.0, A, x, 0.0).

  N = 10;
  int M = 10;
  LDA = N;
  Epetra_SerialDenseMatrix smallA(N, M, false);
  Epetra_SerialDenseMatrix x(N, 1, false);
  Epetra_SerialDenseMatrix y1(N, 1, false);
  Epetra_SerialDenseMatrix y2(N, 1, false);

  for(i=0; i<N; ++i) {
    for(j=0; j<M; ++j) {
      smallA(i,j) = 1.0*i+2.0*j+1.0;
    }
    x(i,0) = 1.0;
    y1(i,0) = 0.0;
    y2(i,0) = 0.0;
  }

  //quick check of operator==
  if (x == y1) {
    if (verbose) cout << "err in Epetra_SerialDenseMatrix::operator==, "
        << "erroneously returned true." << std::endl;
    return(-1);
  }

  //quick check of operator!=
  if (x != x) {
    if (verbose) cout << "err in Epetra_SerialDenseMatrix::operator==, "
        << "erroneously returned true." << std::endl;
    return(-1);
  }

  int err1 = smallA.Multiply(false, x, y1);
  int err2 = y2.Multiply('N','N', 1.0, smallA, x, 0.0);
  if (err1 != 0 || err2 != 0) {
    if (verbose) cout << "err in Epetra_SerialDenseMatrix::Multiply"<<endl;
    return(err1+err2);
  }

  for(i=0; i<N; ++i) {
    if (y1(i,0) != y2(i,0)) {
      if (verbose) cout << "different versions of Multiply don't match."<<endl;
      return(-99);
    }
  }

  // Now test for larger system, both correctness and performance.


  N = 2000;
  NRHS = 5;
  LDA = N;
  LDB = N;
  LDX = N;

  if (verbose) cout << "\n\nComputing factor of an " << N << " x " << N << " general matrix...Please wait.\n\n" << endl;

  // Define A and X

  A = new double[LDA*N];
  X = new double[LDB*NRHS];

  for (j=0; j<N; j++) {
    for (k=0; k<NRHS; k++) X[j+k*LDX] = 1.0/((double) (j+5+k));
    for (i=0; i<N; i++) {
      if (i==((j+2)%N)) A[i+j*LDA] = 100.0 + i;
      else A[i+j*LDA] = -11.0/((double) (i+5)*(j+2));
    }
  }

  // Define Epetra_SerialDenseMatrix object

  Epetra_SerialDenseMatrix BigMatrix(Copy, A, LDA, N, N);
  Epetra_SerialDenseMatrix OrigBigMatrix(View, A, LDA, N, N);

  Epetra_SerialDenseSolver BigSolver;
  BigSolver.FactorWithEquilibration(true);
  BigSolver.SetMatrix(BigMatrix);

  // Time factorization

  Epetra_Flops counter;
  BigSolver.SetFlopCounter(counter);
  Epetra_Time Timer(Comm);
  double tstart = Timer.ElapsedTime();
  ierr = BigSolver.Factor();
  if (ierr!=0 && verbose) cout << "Error in factorization = "<<ierr<< endl;
  assert(ierr==0);
  double time = Timer.ElapsedTime() - tstart;

  double FLOPS = counter.Flops();
  double MFLOPS = FLOPS/time/1000000.0;
  if (verbose) cout << "MFLOPS for Factorization = " << MFLOPS << endl;

  // Define Left hand side and right hand side
  Epetra_SerialDenseMatrix LHS(View, X, LDX, N, NRHS);
  Epetra_SerialDenseMatrix RHS;
  RHS.Shape(N,NRHS); // Allocate RHS

  // Compute RHS from A and X

  Epetra_Flops RHS_counter;
  RHS.SetFlopCounter(RHS_counter);
  tstart = Timer.ElapsedTime();
  RHS.Multiply('N', 'N', 1.0, OrigBigMatrix, LHS, 0.0);
  time = Timer.ElapsedTime() - tstart;

  Epetra_SerialDenseMatrix OrigRHS = RHS;

  FLOPS = RHS_counter.Flops();
  MFLOPS = FLOPS/time/1000000.0;
  if (verbose) cout << "MFLOPS to build RHS (NRHS = " << NRHS <<") = " << MFLOPS << endl;

  // Set LHS and RHS and solve
  BigSolver.SetVectors(LHS, RHS);

  tstart = Timer.ElapsedTime();
  ierr = BigSolver.Solve();
  if (ierr==1 && verbose) cout << "LAPACK guidelines suggest this matrix might benefit from equilibration." << endl;
  else if (ierr!=0 && verbose) cout << "Error in solve = "<<ierr<< endl;
  assert(ierr>=0);
  time = Timer.ElapsedTime() - tstart;

  FLOPS = BigSolver.Flops();
  MFLOPS = FLOPS/time/1000000.0;
  if (verbose) cout << "MFLOPS for Solve (NRHS = " << NRHS <<") = " << MFLOPS << endl;

  double * resid = new double[NRHS];
  bool OK = Residual(N, NRHS, A, LDA, BigSolver.Transpose(), BigSolver.X(), BigSolver.LDX(),
         OrigRHS.A(), OrigRHS.LDA(), resid);

  if (verbose) {
    if (!OK) cout << "************* Residual do not meet tolerance *************" << endl;
    for (i=0; i<NRHS; i++)
      cout << "Residual[" << i <<"] = "<< resid[i] << endl;
    cout  << endl;
  }

  // Solve again using the Epetra_SerialDenseVector class for LHS and RHS

  Epetra_SerialDenseVector X2;
  Epetra_SerialDenseVector B2;
  X2.Size(BigMatrix.N());
  B2.Size(BigMatrix.M());
  int length = BigMatrix.N();
  {for (int kk=0; kk<length; kk++) X2[kk] = ((double ) kk)/ ((double) length);} // Define entries of X2

  RHS_counter.ResetFlops();
  B2.SetFlopCounter(RHS_counter);
  tstart = Timer.ElapsedTime();
  B2.Multiply('N', 'N', 1.0, OrigBigMatrix, X2, 0.0); // Define B2 = A*X2
  time = Timer.ElapsedTime() - tstart;

  Epetra_SerialDenseVector OrigB2 = B2;

  FLOPS = RHS_counter.Flops();
  MFLOPS = FLOPS/time/1000000.0;
  if (verbose) cout << "MFLOPS to build single RHS = " << MFLOPS << endl;

  // Set LHS and RHS and solve
  BigSolver.SetVectors(X2, B2);

  tstart = Timer.ElapsedTime();
  ierr = BigSolver.Solve();
  time = Timer.ElapsedTime() - tstart;
  if (ierr==1 && verbose) cout << "LAPACK guidelines suggest this matrix might benefit from equilibration." << endl;
  else if (ierr!=0 && verbose) cout << "Error in solve = "<<ierr<< endl;
  assert(ierr>=0);

  FLOPS = counter.Flops();
  MFLOPS = FLOPS/time/1000000.0;
  if (verbose) cout << "MFLOPS to solve single RHS = " << MFLOPS << endl;

  OK = Residual(N, 1, A, LDA, BigSolver.Transpose(), BigSolver.X(), BigSolver.LDX(), OrigB2.A(),
    OrigB2.LDA(), resid);

  if (verbose) {
    if (!OK) cout << "************* Residual do not meet tolerance *************" << endl;
      cout << "Residual = "<< resid[0] << endl;
  }
  delete [] resid;
  delete [] A;
  delete [] X;

  // Now test default constructor and index operators

  N = 5;
  Epetra_SerialDenseMatrix C; // Implicit call to default constructor, should not need to call destructor
  C.Shape(5,5); // Make it 5 by 5
  double * C1 = new double[N*N];
  GenerateHilbert(C1, N, N); // Generate Hilber matrix

  C1[1+2*N] = 1000.0;  // Make matrix nonsymmetric

  // Fill values of C with Hilbert values
  for (i=0; i<N; i++)
    for (j=0; j<N; j++)
      C(i,j) = C1[i+j*N];

  // Test if values are correctly written and read
  for (i=0; i<N; i++)
    for (j=0; j<N; j++) {
      assert(C(i,j) == C1[i+j*N]);
      assert(C(i,j) == C[j][i]);
    }

  if (verbose)
    cout << "Default constructor and index operator check OK.  Values of Hilbert matrix = "
   << endl << C << endl
   << "Values should be 1/(i+j+1), except value (1,2) should be 1000" << endl;

  delete [] C1;

  // now test sized/shaped constructor
  Epetra_SerialDenseMatrix shapedMatrix(10, 12);
  assert(shapedMatrix.M() == 10);
  assert(shapedMatrix.N() == 12);
  for(i = 0; i < 10; i++)
    for(j = 0; j < 12; j++)
      assert(shapedMatrix(i, j) == 0.0);
  Epetra_SerialDenseVector sizedVector(20);
  assert(sizedVector.Length() == 20);
  for(i = 0; i < 20; i++)
    assert(sizedVector(i) == 0.0);
  if (verbose)
    cout << "Shaped/sized constructors check OK." << endl;

  // test Copy/View mode in op= and cpy ctr
  int temperr = 0;
  temperr = matrixAssignment(verbose, debug);
  if(verbose && temperr == 0)
    cout << "Operator = checked OK." << endl;
  EPETRA_TEST_ERR(temperr, ierr);
  temperr = matrixCpyCtr(verbose, debug);
  if(verbose && temperr == 0)
    cout << "Copy ctr checked OK." << endl;
  EPETRA_TEST_ERR(temperr, ierr);

  // Test some vector methods

  Epetra_SerialDenseVector v1(3);
  v1[0] = 1.0;
  v1[1] = 3.0;
  v1[2] = 2.0;

  Epetra_SerialDenseVector v2(3);
  v2[0] = 2.0;
  v2[1] = 1.0;
  v2[2] = -2.0;

  temperr = 0;
  if (v1.Norm1()!=6.0) temperr++;
  if (fabs(sqrt(14.0)-v1.Norm2())>1.0e-6) temperr++;
  if (v1.NormInf()!=3.0) temperr++;
  if(verbose && temperr == 0)
    cout << "Vector Norms checked OK." << endl;
  temperr = 0;
  if (v1.Dot(v2)!=1.0) temperr++;
  if(verbose && temperr == 0)
    cout << "Vector Dot product checked OK." << endl;

#ifdef EPETRA_MPI
  MPI_Finalize() ;
#endif

/* end main
*/
return ierr ;
}

int check(Epetra_SerialDenseSolver &solver, double * A1, int LDA1,
    int N1, int NRHS1, double OneNorm1,
    double * B1, int LDB1,
    double * X1, int LDX1,
    bool Transpose, bool verbose) {

  int i;
  bool OK;
  // Test query functions

  int M= solver.M();
  if (verbose) cout << "\n\nNumber of Rows = " << M << endl<< endl;
  assert(M==N1);

  int N= solver.N();
  if (verbose) cout << "\n\nNumber of Equations = " << N << endl<< endl;
  assert(N==N1);

  int LDA = solver.LDA();
  if (verbose) cout << "\n\nLDA = " << LDA << endl<< endl;
  assert(LDA==LDA1);

  int LDB = solver.LDB();
  if (verbose) cout << "\n\nLDB = " << LDB << endl<< endl;
  assert(LDB==LDB1);

  int LDX = solver.LDX();
  if (verbose) cout << "\n\nLDX = " << LDX << endl<< endl;
  assert(LDX==LDX1);

  int NRHS = solver.NRHS();
  if (verbose) cout << "\n\nNRHS = " << NRHS << endl<< endl;
  assert(NRHS==NRHS1);

  assert(solver.ANORM()==-1.0);
  assert(solver.RCOND()==-1.0);
  if (!solver.A_Equilibrated() && !solver.B_Equilibrated()) {
    assert(solver.ROWCND()==-1.0);
    assert(solver.COLCND()==-1.0);
    assert(solver.AMAX()==-1.0);
  }


  // Other binary tests

  assert(!solver.Factored());
  assert(solver.Transpose()==Transpose);
  assert(!solver.SolutionErrorsEstimated());
  assert(!solver.Inverted());
  assert(!solver.ReciprocalConditionEstimated());
  assert(!solver.Solved());

  assert(!solver.SolutionRefined());


  int ierr = solver.Factor();
  assert(ierr>-1);
  if (ierr!=0) return(ierr); // Factorization failed due to poor conditioning.
  double rcond;
  ierr = solver.ReciprocalConditionEstimate(rcond);
  assert(ierr==0);
  if (verbose) {

    double rcond1 = 1.0/exp(3.5*((double)N));
    if (N==1) rcond1 = 1.0;
    cout << "\n\nRCOND = "<< rcond << " should be approx = "
        << rcond1 << endl << endl;
  }

  ierr = solver.Solve();
  assert(ierr>-1);
  if (ierr!=0 && verbose) cout << "LAPACK rules suggest system should be equilibrated." << endl;

  assert(solver.Factored());
  assert(solver.Transpose()==Transpose);
  assert(solver.ReciprocalConditionEstimated());
  assert(solver.Solved());

  if (solver.SolutionErrorsEstimated()) {
    if (verbose) {
      cout << "\n\nFERR[0] = "<< solver.FERR()[0] << endl;
      cout << "\n\nBERR[0] = "<< solver.BERR()[0] << endl<< endl;
    }
  }

  double * resid = new double[NRHS];
  OK = Residual(N, NRHS, A1, LDA1, solver.Transpose(), solver.X(), solver.LDX(), B1, LDB1, resid);
  if (verbose) {
    if (!OK) cout << "************* Residual do not meet tolerance *************" << endl;
 /*
    if (solver.A_Equilibrated()) {
      double * R = solver.R();
      double * C = solver.C();
      for (i=0; i<solver.M(); i++)
      cout << "R[" << i <<"] = "<< R[i] << endl;
      for (i=0; i<solver.N(); i++)
      cout << "C[" << i <<"] = "<< C[i] << endl;
    }
 */
    cout << "\n\nResiduals using factorization to solve" << endl;
    for (i=0; i<NRHS; i++)
      cout << "Residual[" << i <<"] = "<< resid[i] << endl;
    cout  << endl;
  }


  ierr = solver.Invert();
  assert(ierr>-1);

  assert(solver.Inverted());
  assert(!solver.Factored());
  assert(solver.Transpose()==Transpose);


  Epetra_SerialDenseMatrix RHS1(Copy, B1, LDB1, N, NRHS);
  Epetra_SerialDenseMatrix LHS1(Copy, X1, LDX1, N, NRHS);
  assert(solver.SetVectors(LHS1, RHS1)==0);
  assert(!solver.Solved());

  assert(solver.Solve()>-1);
  


  OK = Residual(N, NRHS, A1, LDA1, solver.Transpose(), solver.X(), solver.LDX(), B1, LDB1, resid);

  if (verbose) {
    if (!OK) cout << "************* Residual do not meet tolerance *************" << endl;
    cout << "Residuals using inverse to solve" << endl;
    for (i=0; i<NRHS; i++)
      cout << "Residual[" << i <<"] = "<< resid[i] << endl;
    cout  << endl;
  }
  delete [] resid;


  return(0);
}

 void GenerateHilbert(double *A, int LDA, int N) {
   for (int j=0; j<N; j++)
     for (int i=0; i<N; i++)
       A[i+j*LDA] = 1.0/((double)(i+j+1));
   return;
 }

bool Residual( int N, int NRHS, double * A, int LDA, bool Transpose,
         double * X, int LDX, double * B, int LDB, double * resid) {

  Epetra_BLAS Blas;
  char Transa = 'N';
  if (Transpose) Transa = 'T';
  Blas.GEMM(Transa, 'N', N, NRHS, N, -1.0, A, LDA,
      X, LDX, 1.0, B, LDB);
  bool OK = true;
  for (int i=0; i<NRHS; i++) {
    resid[i] = Blas.NRM2(N, B+i*LDB);
    if (resid[i]>1.0E-7) OK = false;
  }

  return(OK);
}


//=========================================================================
// test matrix operator= (copy & view)
int matrixAssignment(bool verbose, bool debug) {
  int ierr = 0;
  int returnierr = 0;
  if(verbose) printHeading("Testing matrix operator=");

  // each section is in its own block so we can reuse variable names
  // lhs = left hand side, rhs = right hand side
  
  {
    // copy->copy (more space needed)
    // orig and dup should have same signature
    // modifying orig or dup should have no effect on the other
    if(verbose) cout << "Checking copy->copy (new alloc)" << endl;
    Epetra_SerialDenseMatrix lhs(2,2);
    double* rand1 = getRandArray(25);
    Epetra_SerialDenseMatrix rhs(Copy, rand1, 5, 5, 5);
    if(debug) {
      cout << "before assignment:" << endl;
      printMat("rhs",rhs);
      printMat("lhs",lhs);
    }
    lhs = rhs;
    if(debug) {
      cout << "after assignment:" << endl;
      printMat("rhs",rhs);
      printMat("lhs",lhs);
    }
    EPETRA_TEST_ERR(!identicalSignatures(rhs,lhs), ierr);
    EPETRA_TEST_ERR(!seperateData(rhs,lhs), ierr);
    delete[] rand1;
  }
  returnierr += ierr;
  if(ierr == 0)
    if(verbose) cout << "Checked OK." << endl;
  ierr = 0;
  {
    // copy->copy (have enough space)
    // orig and dup should have same signature
    // modifying orig or dup should have no effect on the other
    if(verbose) cout << "\nChecking copy->copy (no alloc)" << endl;
    double* rand1 = getRandArray(25);
    double* rand2 = getRandArray(20);
    Epetra_SerialDenseMatrix lhs(Copy, rand1, 5, 5, 5);
    Epetra_SerialDenseMatrix rhs(Copy, rand2, 4, 4, 5);
    double* origA = lhs.A();
    int origLDA = lhs.LDA();
    if(debug) {
      cout << "before assignment:" << endl;
      printMat("rhs",rhs);
      printMat("lhs",lhs);
    }
    lhs = rhs;
    if(debug) {
      cout << "after assignment:" << endl;
      printMat("rhs",rhs);
      printMat("lhs",lhs);
    }
    // in this case, instead of doing a "normal" LDA test in identSig,
    // we do our own. Since we had enough space already, A and LDA should
    // not have been changed by the assignment. (The extra parameter to
    // identicalSignatures tells it not to test LDA).
    EPETRA_TEST_ERR((lhs.A() != origA) || (lhs.LDA() != origLDA), ierr);
    EPETRA_TEST_ERR(!identicalSignatures(rhs,lhs,false), ierr);
    EPETRA_TEST_ERR(!seperateData(rhs,lhs), ierr);
  }
  returnierr += ierr;
  if(ierr == 0)
    if(verbose) cout << "Checked OK." << endl;
  ierr = 0;
  {
    // view->copy
    // orig and dup should have same signature
    // modifying orig or dup should have no effect on the other
    if(verbose) cout << "\nChecking view->copy" << endl;
    double* rand1 = getRandArray(25);
    double* rand2 = getRandArray(64);
    Epetra_SerialDenseMatrix lhs(View, rand1, 5, 5, 5);
    Epetra_SerialDenseMatrix rhs(Copy, rand2, 8, 8, 8);
    if(debug) {
      cout << "before assignment:" << endl;
      printMat("rhs",rhs);
      printMat("lhs",lhs);
    }
    lhs = rhs;
    if(debug) {
      cout << "after assignment:" << endl;
      printMat("rhs",rhs);
      printMat("lhs",lhs);
    }
    EPETRA_TEST_ERR(!identicalSignatures(rhs,lhs), ierr);
    EPETRA_TEST_ERR(!seperateData(rhs,lhs), ierr);
    delete[] rand1;
    delete[] rand2;
  }
  returnierr += ierr;
  if(ierr == 0)
    if(verbose) cout << "Checked OK." << endl;
  ierr = 0;
  {
    // copy->view
    // orig and dup should have same signature
    // modifying orig or dup should change the other
    if(verbose) cout << "\nChecking copy->view" << endl;
    double* rand1 = getRandArray(10);
    Epetra_SerialDenseMatrix lhs(4,4);
    Epetra_SerialDenseMatrix rhs(View, rand1, 2, 2, 5);
    if(debug) {
      cout << "before assignment:" << endl;
      printMat("rhs",rhs);
      printMat("lhs",lhs);
    }
    lhs = rhs;
    if(debug) {
      cout << "after assignment:" << endl;
      printMat("rhs",rhs);
      printMat("lhs",lhs);
    }
    EPETRA_TEST_ERR(!identicalSignatures(rhs,lhs), ierr);
    EPETRA_TEST_ERR(seperateData(rhs,lhs), ierr);
    delete[] rand1;
  }
  returnierr += ierr;
  if(ierr == 0)
    if(verbose) cout << "Checked OK." << endl;
  ierr = 0; 
  {
    // view->view
    // orig and dup should have same signature
    // modifying orig or dup should change the other
    if(verbose) cout << "\nChecking view->view" << endl;
    double* rand1 = getRandArray(9);
    double* rand2 = getRandArray(18);
    Epetra_SerialDenseMatrix lhs(View, rand1, 3, 3, 3);
    Epetra_SerialDenseMatrix rhs(View, rand2, 3, 3, 6);
    if(debug) {
      cout << "before assignment:" << endl;
      printMat("rhs",rhs);
      printMat("lhs",lhs);
    }
    lhs = rhs;
    if(debug) {
      cout << "after assignment:" << endl;
      printMat("rhs",rhs);
      printMat("lhs",lhs);
    }
    EPETRA_TEST_ERR(!identicalSignatures(rhs,lhs), ierr);
    EPETRA_TEST_ERR(seperateData(rhs,lhs), ierr);
    delete[] rand1;
    delete[] rand2;
  }
  returnierr += ierr;
  if(ierr == 0)
    if(verbose) cout << "Checked OK." << endl;
  ierr = 0;

  return(returnierr);
}

//=========================================================================
// test matrix copy constructor (copy & view)
int matrixCpyCtr(bool verbose, bool debug) {
  const int m1rows = 5;
  const int m1cols = 4;
  const int m2rows = 2;
  const int m2cols = 6;

  int ierr = 0;
  int returnierr = 0;
  if(verbose) printHeading("Testing matrix copy constructors");

  if(verbose) cout << "checking copy constructor (view)" << endl;
  double* m1rand = getRandArray(m1rows * m1cols);
  if(debug) printArray(m1rand, m1rows * m1cols);
  Epetra_SerialDenseMatrix m1(View, m1rand, m1rows, m1rows, m1cols);
  if(debug) {
    cout << "original matrix:" << endl;
    printMat("m1",m1);
  }
  Epetra_SerialDenseMatrix m1clone(m1);
  if(debug) {
    cout << "clone matrix:" << endl;
    printMat("m1clone",m1clone);
  }
  if(verbose) cout << "making sure signatures match" << endl;
  EPETRA_TEST_ERR(!identicalSignatures(m1, m1clone), ierr);
  delete[] m1rand;
  returnierr += ierr;
  if(ierr == 0)
    if(verbose) cout << "Checked OK." << endl;
  ierr = 0;
  
  if(verbose) cout << "\nchecking copy constructor (copy)" << endl;
  double* m2rand = getRandArray(m2rows * m2cols);
  if(debug) printArray(m2rand, m2rows * m2cols);
  Epetra_SerialDenseMatrix m2(Copy, m2rand, m2rows, m2rows, m2cols);
  if(debug) {
    cout << "original matrix:" << endl;
    printMat("m2",m2);
  }
  Epetra_SerialDenseMatrix m2clone(m2);
  if(debug) {
    cout << "clone matrix:" << endl;
    printMat("m2clone",m2clone);
  }
  if(verbose) cout << "checking that signatures match" << endl;
  EPETRA_TEST_ERR(!identicalSignatures(m2, m2clone), ierr);
  returnierr += ierr;
  if(ierr == 0)
    if(verbose) cout << "Checked OK." << endl;
  ierr = 0;

  if(verbose) cout << "\nmodifying entry in m2, m2clone should be unchanged" << endl;
  EPETRA_TEST_ERR(!seperateData(m2, m2clone), ierr);
  if(debug) {
    printArray(m2rand, m2rows * m2cols);
    cout << "orig:" << endl;
    printMat("m2",m2);
    cout << "clone:" << endl;
    printMat("m2clone",m2clone);
  }
  delete[] m2rand;
  returnierr += ierr;
  if(ierr == 0)
    if(verbose) cout << "Checked OK." << endl;
  ierr = 0;
  
  return(returnierr);
}

//=========================================================================
// prints section heading with spacers/formatting
void printHeading(const char* heading) {
  cout << "\n==================================================================\n";
  cout << heading << endl;
  cout << "==================================================================\n";
}

//=========================================================================
// prints SerialDenseMatrix/Vector with formatting
void printMat(const char* name, Epetra_SerialDenseMatrix& matrix) {
  //cout << "--------------------" << endl;
  cout << "*** " << name << " ***" << endl;
  cout << matrix;
  //cout << "--------------------" << endl;
}

//=========================================================================
// prints double* array with formatting
void printArray(double* array, int length) {
  cout << "user array (size " << length << "): ";
  for(int i = 0; i < length; i++)
    cout << array[i] << "  ";
  cout << endl;
}

//=========================================================================
// returns a double* array of a given length, with random values on interval (-1,1).
// this is the same generator used in SerialDenseMatrix
double* getRandArray(int length) {
  const double a = 16807.0;
  const double BigInt = 2147483647.0;
  const double DbleOne = 1.0;
  const double DbleTwo = 2.0;
  double seed = rand();

  double* array = new double[length];

  for(int i = 0; i < length; i++) {
    seed = fmod(a * seed, BigInt);
    array[i] = DbleTwo * (seed / BigInt) - DbleOne;
  }

  return(array);
}

//=========================================================================
// checks the signatures of two matrices
bool identicalSignatures(Epetra_SerialDenseMatrix& a, Epetra_SerialDenseMatrix& b, bool testLDA) {

  if((a.M()  != b.M()  )|| // check properties first
     (a.N()  != b.N()  )||
     (a.CV() != b.CV() ))
    return(false);

  if(testLDA == true)      // if we are coming from op= c->c #2 (have enough space)
    if(a.LDA() != b.LDA()) // then we don't check LDA (but we do check it in the test function)
      return(false);

  if(a.CV() == View) { // if we're still here, we need to check the data
    if(a.A() != b.A()) // for a view, this just means checking the pointers
      return(false);   // for a copy, this means checking each element
  }
  else { // CV == Copy
    const int m = a.M();
    const int n = a.N();
    for(int i = 0; i < m; i++)
      for(int j = 0; j < n; j++) {
        if(a(i,j) != b(i,j))
          return(false);
      }
  }

  return(true); // if we're still here, signatures are identical
}

//=========================================================================
// checks if two matrices are independent or not
bool seperateData(Epetra_SerialDenseMatrix& a, Epetra_SerialDenseMatrix& b) {
  bool seperate;

  int r = EPETRA_MIN(a.M(),b.M()) / 2; // ensures (r,c) is valid
  int c = EPETRA_MIN(a.N(),b.N()) / 2; // in both matrices

  double orig_a = a(r,c);
  double new_value = a(r,c) + 1;
  if(b(r,c) == new_value) // there's a chance b could be independent, but
    new_value++;          // already have new_value in (r,c).
  
  a(r,c) = new_value;
  if(b(r,c) == new_value)
    seperate = false;
  else
    seperate = true;

  a(r,c) = orig_a; // undo change we made to a

  return(seperate);
}