// computes the frobenius norm of A, returns it in frobnorm
void computeFrobNorm(const double *localRowChunk, double * frobnorm, const distMatrixInfo *matInfo) {
int mpi_rank = matInfo->mpi_rank;
int numcols = matInfo->numcols;
int localrows = matInfo->localrows;
MPI_Comm *comm = matInfo->comm;
double frobnormsquared;
*frobnorm = LAPACKE_dlange(LAPACK_ROW_MAJOR, 'F', localrows, numcols, localRowChunk, numcols);
frobnormsquared = pow(*frobnorm, 2);
MPI_Reduce(&frobnormsquared, frobnorm, 1, MPI_DOUBLE, MPI_SUM, 0, *comm);
if (mpi_rank == 0) {
*frobnorm = sqrt(*frobnorm);
}
}
DLLEXPORT double d_matrix_norm(char norm, lapack_int m, lapack_int n, double a[])
{
return LAPACKE_dlange(LAPACK_COL_MAJOR, norm, m, n, a, m);
}
/* Main program */
int main() {
/* Locals */
lapack_int n = N, nrhs = NRHS, lda = LDA, ldb = LDB, info;
/* Local arrays */
lapack_int ipiv[N];
double a[LDA*N] = {
6.80, -6.05, -0.45, 8.32, -9.67,
-2.11, -3.30, 2.58, 2.71, -5.14,
5.66, 5.36, -2.70, 4.35, -7.26,
5.97, -4.44, 0.27, -7.17, 6.08,
8.23, 1.08, 9.04, 2.14, -6.87
};
double b[LDB*N] = {
4.02, -1.56, 9.81,
6.19, 4.00, -4.09,
-8.22, -8.67, -4.57,
-7.57, 1.75, -8.61,
-3.03, 2.86, 8.99
};
double aNorm;
double rcond;
char ONE_NORM = '1';
lapack_int NROWS = n;
lapack_int NCOLS = n;
lapack_int LEADING_DIMENSION_A = n;
/* Print Entry Matrix */
print_matrix( "Entry Matrix A", n, n, a, lda );
/* Print Right Rand Side */
print_matrix( "Right Rand Side", n, nrhs, b, ldb );
printf( "\n" );
/* Executable statements */
printf( "LAPACKE_dgecon Example Program Results\n" );
aNorm = LAPACKE_dlange(LAPACK_ROW_MAJOR, ONE_NORM, NROWS, NCOLS, a, LEADING_DIMENSION_A);
info = LAPACKE_dgetrf(LAPACK_ROW_MAJOR, NROWS, NCOLS, a, LEADING_DIMENSION_A, ipiv);
info = LAPACKE_dgecon(LAPACK_ROW_MAJOR, ONE_NORM, n, a, LEADING_DIMENSION_A, aNorm, &rcond); // aNorm should be 35.019999999999996
double work[4*N];
int iwork[N];
//info = LAPACKE_dgecon_work(LAPACK_ROW_MAJOR, ONE_NORM, n, a, LEADING_DIMENSION_A, aNorm, &rcond, work, iwork); // aNorm should be 35.019999999999996
//dgecon_( &ONE_NORM, &n, a, &LEADING_DIMENSION_A, &aNorm, &rcond, work, iwork, &info );
/* Check for the exact singularity */
if (info == 0)
{
printf("LAPACKE_dgecon completed SUCCESSFULLY...\n");
}
else if ( info < 0 )
{
printf( "Element %d of A had an illegal value\n", -info );
exit( 1 );
}
else
{
printf( "Unrecognized value of INFO = %d\n", info );
exit( 1 );
}
/* Print solution */
printf("LAPACKE_dlange / One-norm of A = %lf\n", aNorm);
printf("LAPACKE_dgecon / RCOND of A = %f\n", rcond);
exit( 0 );
} /* End of LAPACKE_dgesv Example */