SymmMatrix(const Matrix *m0, int p)
: symm1_next(0), R(m0->get_ring()), ncols(m0->n_cols()), m(m0), result()
{
const FreeModule *Fp = m0->rows()->symm(p);
const FreeModule *Gp = m0->cols()->symm(p);
int *dp = R->degree_monoid()->make_new(m->degree_shift());
R->degree_monoid()->power(dp, p, dp);
result = MatrixConstructor(Fp, Gp, dp);
if (p >= 0)
{
vec f = R->e_sub_i(0);
symm1(f, 0, p); // consumes f
}
}
PfaffianComputation::PfaffianComputation(const Matrix *M0, int p0)
: R(M0->get_ring()),
M(M0),
p(p0),
done(false),
row_set(0)
{
pfaffs = MatrixConstructor(R->make_FreeModule(1),0);
if (p == 0)
{
pfaffs.append(R->make_vec(0,R->one()));
done = true;
return;
}
if (p % 2 != 0 || p < 0 || (p > M->n_cols()) || (p > M->n_rows()))
{
done = true;
return;
}
row_set = newarray_atomic(int,p);
for (int i=0; i<p; i++) row_set[i] = i;
}
DetComputation::DetComputation(const Matrix *M0, int p0,
bool do_exterior0,
int strategy0)
: R(M0->get_ring()),
M(M0),
done(false),
p(p0),
do_exterior(do_exterior0),
strategy(strategy0),
row_set(NULL),
col_set(NULL),
this_row(0),
this_col(0),
D(0)
{
if (do_exterior)
{
F = M->rows()->exterior(p);
FreeModule *G = M->cols()->exterior(p);
int *deg = R->degree_monoid()->make_new(M->degree_shift());
R->degree_monoid()->power(deg, p, deg);
result = MatrixConstructor(F,G,deg);
R->degree_monoid()->remove(deg);
}
else
{
F = R->make_FreeModule(1);
result = MatrixConstructor(F,0);
}
// Handle trivial cases
if (p < 0)
{
// In either case, want a zero matrix
done = true;
return;
}
if (p == 0)
{
// We want a single element which is '1'
if (do_exterior)
result.set_entry(0,0,R->one());
else
result.append(R->make_vec(0,R->one()));
done = true;
return;
}
if (p > M->n_rows() || p > M->n_cols())
{
// Zero matrix in either case
done = true;
return;
}
done = false;
row_set = newarray_atomic(size_t,p);
col_set = newarray_atomic(size_t,p);
for (size_t i=0; i<p; i++)
{
row_set[i] = i;
col_set[i] = i;
}
D = newarray(ring_elem *,p);
for (size_t i=0; i<p; i++)
{
D[i] = newarray(ring_elem,p);
for (size_t j=0; j<p;j++) D[i][j] = ZERO_RINGELEM;
}
}
void DetComputation::clear()
{
if (do_exterior) return;
result = MatrixConstructor(F,0);
}
