JNIEXPORT void JNICALL Java_uncomplicate_neanderthal_CBLAS_drotg
(JNIEnv *env, jclass clazz, jobject params) {
double *ca = (double *) (*env)->GetDirectBufferAddress(env, params);
double *cb = ca + 1;
double *cc = ca + 2;
double *cs = ca + 3;
cblas_drotg(ca, cb, cc, cs);
};
JNIEXPORT void JNICALL Java_uncomplicate_neanderthal_CBLAS_drotg
(JNIEnv *env, jclass clazz, jobject abcs, jint offset_abcs, jint inc_abcs) {
double *c_abcs = (double *) (*env)->GetDirectBufferAddress(env, abcs) + offset_abcs;
cblas_drotg(c_abcs, c_abcs + inc_abcs, c_abcs + 2 * inc_abcs, c_abcs + 3 * inc_abcs);
};
void My_drotg(double* a, double* b, double* c, double* s)
{
cblas_drotg(a,b,c,s);
}
//
// Overloaded function for dispatching to
// * CBLAS backend, and
// * double value-type.
//
inline void rotg( double& a, double& b, double& c, double& s ) {
cblas_drotg( &a, &b, &c, &s );
}
void F77_drotg( double *a, double *b, double *c, double *s)
{
cblas_drotg(a,b,c,s);
return;
}
// Given row and column permutations compute the QR decomposition of a
// sparse matrix.
void sparse_qr_decomp( const int *P1,
sparse_mat *A,
const int *P2,
sparse_mat **Q,
sparse_mat **R )
{
// Components of the R matrix:
int nnz, *is, *js;
double *vs;
// Allocate structures to store Q and R.
sparse_vec **rows = (sparse_vec**)calloc( A->m, sizeof(sparse_vec*) );
rotation *grots = alloc_rotation( A->m );
// Work variables
int i, j, *col;
double a, b, c, s, r, *val;
sparse_vec row, *row_i, *row_j;
grots -> n = A -> m;
permute_rows(P1, A);
permute_cols(A, P2);
for( j = 0; j < A->m; ++j ) {
row(*A,j,row);
row_j = rows[j] = copy_sparse_vec( &row );
if( row_j->nnz > 0 ) {
i = *(row_j->is);
b = *(row_j->vs);
while( i < j ) {
row_i = rows[i];
if( row_i->nnz == 0 || *(row_i->is) > i )
a = 0.0;
else
a = *(row_i->vs);
cblas_drotg( &a, &b, &c, &s );
sp_apply_grot( c, s, rows+i, rows+j );
left_comp_rotation( &grots, i, j, c, s );
row_j = rows[j];
if( row_j->nnz == 0 ) break;
i = *(row_j->is);
b = *(row_j->vs);
}
}
}
*Q = sparse_mat_rotation( grots );
*R = sparse_mat_rows( A->n, rows );
free_rotation( grots );
for( j = 0; j < A->m; ++j )
free( rows[j] );
free( rows );
}
