MutableMatrix *MutableMatrix::identity(const Ring *R, size_t nrows, bool dense)
{
MutableMatrix *result = MutableMatrix::zero_matrix(R,nrows,nrows,dense);
for (size_t i=0; i<nrows; i++)
result->set_entry(i,i,R->from_long(1));
return result;
}
void F4GB::show_matrix()
{
// Debugging routine
MutableMatrix *q = F4toM2Interface::to_M2_MutableMatrix(KK,mat,gens,gb);
buffer o;
q->text_out(o);
emit(o.str());
}
MutableMatrix* ResF4toM2Interface::to_M2_MutableMatrix(
const Ring* K,
SchreyerFrame& C,
int lev,
int degree)
{
// Now we loop through the elements of degree 'degree' at level 'lev'
auto& thislevel = C.level(lev);
int n = 0;
for (auto p=thislevel.begin(); p != thislevel.end(); ++p)
{
if (p->mDegree == degree) n++;
}
auto& prevlevel = C.level(lev-1);
int* newcomps = new int[prevlevel.size()];
int nextcomp = 0;
for (int i=0; i<prevlevel.size(); i++)
if (prevlevel[i].mDegree == degree)
newcomps[i] = nextcomp++;
else
newcomps[i] = -1;
// create the mutable matrix
MutableMatrix* result = MutableMatrix::zero_matrix(K,
nextcomp,
n,
true);
// Now loop through the elements at thislevel,
// and for each, loop through the terms of mSyzygy.
// if the component x satisfies newcomps[x] >= 0, then place
// this coeff into the mutable matrix.
int col = 0;
for (auto p=thislevel.begin(); p != thislevel.end(); ++p)
{
if (p->mDegree != degree) continue;
auto& f = p->mSyzygy;
auto end = poly_iter(C.ring(), f, 1);
auto i = poly_iter(C.ring(), f);
for ( ; i != end; ++i)
{
long comp = C.monoid().get_component(i.monomial());
if (newcomps[comp] >= 0)
{
ring_elem a;
a = K->from_long(C.ring().resGausser().coeff_to_int(i.coefficient()));
result->set_entry(newcomps[comp], col, a);
}
}
++col;
}
delete [] newcomps;
return result;
}
MutableMatrix *MutableMatrix::from_matrix(const Matrix *m, bool prefer_dense)
{
MutableMatrix *result = zero_matrix(m->get_ring(),
m->n_rows(),
m->n_cols(),
prefer_dense);
Matrix::iterator i(m);
for (unsigned int c=0; c<m->n_cols(); c++)
{
for (i.set(c); i.valid(); i.next())
result->set_entry(i.row(), c, i.entry());
}
return result;
}
void F4GB::show_new_rows_matrix()
{
int ncols = INTSIZE(mat->columns);
int nrows = 0;
for (int nr=0; nr<mat->rows.size(); nr++)
if (is_new_GB_row(nr)) nrows++;
MutableMatrix *gbM = IM2_MutableMatrix_make(KK->get_ring(), nrows, ncols, false);
int r = -1;
for (int nr=0; nr<mat->rows.size(); nr++)
if (is_new_GB_row(nr))
{
r++;
row_elem &row = mat->rows[nr];
ring_elem *rowelems = newarray(ring_elem, row.len);
if (row.coeffs == 0)
{
if (row.monom == 0)
KK->to_ringelem_array(row.len, gens[row.elem]->f.coeffs, rowelems);
else
KK->to_ringelem_array(row.len, gb[row.elem]->f.coeffs, rowelems);
}
else
{
KK->to_ringelem_array(row.len, row.coeffs, rowelems);
}
for (int i=0; i<row.len; i++)
{
int c = row.comps[i];
gbM->set_entry(r,c,rowelems[i]);
}
deletearray(rowelems);
}
buffer o;
gbM->text_out(o);
emit(o.str());
}
