const Ring /* or null */ *IM2_Ring_quotient(const Ring *R, const Matrix *I)
{
try
{
if (I->get_ring() != R)
{
ERROR("expected matrix to be over the same ring");
}
if (I->n_rows() != 1)
{
ERROR("expected a one row matrix of quotient elements");
return 0;
}
const PolynomialRing *P = R->cast_to_PolynomialRing();
if (P == 0)
{
ERROR("expected a polynomial ring");
return 0;
}
PolynomialRing *result = PolynomialRing::create_quotient(P, I);
intern_polyring(result);
return result;
} catch (exc::engine_error e)
{
ERROR(e.what());
return NULL;
}
}
const Ring /* or null */ *IM2_Ring_quotient1(const Ring *R, const Ring *B)
/* R is a poly ring of the form A[x], B = A/I, constructs A[x]/I */
/* if R is a polynomial ring of the form A[x]/J, and B = A/I (where A is a poly
ring)
then form the quotient ring B[x]/J. */
{
try
{
const PolynomialRing *R1 = R->cast_to_PolynomialRing();
const PolynomialRing *B1 = B->cast_to_PolynomialRing();
if (R1 == 0 || B1 == 0)
{
ERROR("expected a polynomial ring");
return 0;
}
if (R1->n_quotients() > 0)
{
ERROR("encountered quotient polynomial ring");
return 0;
}
PolynomialRing *result = PolyRingQuotient::create_quotient(R1, B1);
intern_polyring(result);
return result;
} catch (exc::engine_error e)
{
ERROR(e.what());
return NULL;
}
}
const Ring /* or null */ *IM2_Ring_skew_polyring(const Ring *R,
M2_arrayint skewvars)
{
try {
#if 0
// const PolyQQ *RQ = R->cast_to_PolyQQ();
// if (RQ != 0)
// {
// const PolyRing *P = SkewPolynomialRing::create(globalZZ,
// RQ->getMonoid(),
// skewvars);
// return PolyQQ::create(P);
// }
#endif
const PolynomialRing *P = R->cast_to_PolynomialRing();
if (P == 0)
{
ERROR("expected a polynomial ring");
return 0;
}
SkewPolynomialRing *result =
SkewPolynomialRing::create(P->getCoefficients(),
P->getMonoid(),
skewvars);
intern_polyring(result);
return result;
}
catch (exc::engine_error e) {
ERROR(e.what());
return NULL;
}
}
const Ring /* or null */ *IM2_Ring_weyl_algebra(const Ring *R,
M2_arrayint comm_vars,
M2_arrayint diff_vars,
int homog_var)
{
try
{
const PolynomialRing *P = R->cast_to_PolynomialRing();
if (P == 0)
{
ERROR("expected a polynomial ring");
return 0;
}
WeylAlgebra *result = WeylAlgebra::create(P->getCoefficients(),
P->getMonoid(),
diff_vars,
comm_vars,
homog_var);
intern_polyring(result);
return result;
} catch (exc::engine_error e)
{
ERROR(e.what());
return NULL;
}
}
const Ring /* or null */ *IM2_Ring_polyring(const Ring *K, const Monoid *M)
{
try
{
const PolyRing *result = PolyRing::create(K, M);
intern_polyring(result);
return result;
} catch (exc::engine_error e)
{
ERROR(e.what());
return NULL;
}
}
const Ring * /* or null */ rawDividedPowerRing(const Ring *K, const Monoid *M)
{
#if 0
//TODO: MES, this function has not yet been implemented, or even placed in engine.h
try {
const DividedPowerRing * result = 0; // DividedPowerRing::create(K,M);
intern_polyring(result);
return result;
}
catch (exc::engine_error e) {
ERROR(e.what());
return NULL;
}
#endif
ERROR("not yet implemented");
return 0;
}
const Ring /* or null */ *IM2_Ring_schur(const Ring *R)
{
try {
const PolynomialRing *P = R->cast_to_PolynomialRing();
if (P == 0)
{
ERROR("Schur ring construction: expected a polynomial ring");
return 0;
}
SchurRing *result = SchurRing::create(P);
intern_polyring(result);
return result;
}
catch (exc::engine_error e) {
ERROR(e.what());
return NULL;
}
}
const Ring /* or null */ *IM2_Ring_solvable_algebra(const Ring *R,
const Matrix *Q)
{
try {
const PolynomialRing *P = R->cast_to_PolynomialRing();
if (P == 0)
{
ERROR("expected a polynomial ring");
return 0;
}
SolvableAlgebra *result = SolvableAlgebra::create(P, Q);
intern_polyring(result);
return result;
}
catch (exc::engine_error e) {
ERROR(e.what());
return NULL;
}
}
const Ring /* or null */ *IM2_Ring_polyring(const Ring *K, const Monoid *M)
{
try {
#if 0
// if (K == globalQQ)
// {
// const PolyRing *P = PolyRing::create(globalZZ,M);
// return PolyQQ::create(P);
// }
#endif
const PolyRing *result = PolyRing::create(K,M);
intern_polyring(result);
return result;
}
catch (exc::engine_error e) {
ERROR(e.what());
return NULL;
}
}
const Ring /* or null */ *IM2_Ring_skew_polyring(const Ring *R,
M2_arrayint skewvars)
{
try
{
const PolynomialRing *P = R->cast_to_PolynomialRing();
if (P == 0)
{
ERROR("expected a polynomial ring");
return 0;
}
SkewPolynomialRing *result = SkewPolynomialRing::create(
P->getCoefficients(), P->getMonoid(), skewvars);
intern_polyring(result);
return result;
} catch (exc::engine_error e)
{
ERROR(e.what());
return NULL;
}
}
const Ring /* or null */ *IM2_Ring_weyl_algebra(const Ring *R,
M2_arrayint comm_vars,
M2_arrayint diff_vars,
int homog_var)
{
try {
#if 0
// const PolyQQ *RQ = R->cast_to_PolyQQ();
// if (RQ != 0)
// {
// const WeylAlgebra *P = WeylAlgebra::create(globalZZ,
// RQ->getMonoid(),
// diff_vars,
// comm_vars,
// homog_var);
// return PolyQQ::create(P);
// }
#endif
const PolynomialRing *P = R->cast_to_PolynomialRing();
if (P == 0)
{
ERROR("expected a polynomial ring");
return 0;
}
WeylAlgebra *result = WeylAlgebra::create(P->getCoefficients(),
P->getMonoid(),
diff_vars,
comm_vars,
homog_var);
intern_polyring(result);
return result;
}
catch (exc::engine_error e) {
ERROR(e.what());
return NULL;
}
}
