/** Removes equalities involving only parameters, but starting from a
* Polyhedron and its context.
* @param P the polyhedron
* @param C P's context
* @param renderSpace: 0 for the parameter space, =1 for the combined space.
* @maxRays Polylib's usual <i>workspace</i>.
*/
Polyhedron * Polyhedron_Remove_parm_eqs(Polyhedron ** P, Polyhedron ** C,
int renderSpace,
unsigned int ** elimParms,
int maxRays) {
Matrix * Eqs;
Polyhedron * Peqs;
Matrix * M = Polyhedron2Constraints((*P));
Matrix * Ct = Polyhedron2Constraints((*C));
/* if the Minkowski representation is not computed yet, do not compute it in
Constraints2Polyhedron */
if (F_ISSET((*P), POL_VALID | POL_INEQUALITIES) &&
(F_ISSET((*C), POL_VALID | POL_INEQUALITIES))) {
FL_INIT(maxRays, POL_NO_DUAL);
}
Eqs = Constraints_Remove_parm_eqs(&M, &Ct, renderSpace, elimParms);
Peqs = Constraints2Polyhedron(Eqs, maxRays);
Matrix_Free(Eqs);
/* particular case: no equality involving only parms is found */
if (Eqs->NbRows==0) {
Matrix_Free(M);
Matrix_Free(Ct);
return Peqs;
}
Polyhedron_Free(*P);
Polyhedron_Free(*C);
(*P) = Constraints2Polyhedron(M, maxRays);
(*C) = Constraints2Polyhedron(Ct, maxRays);
Matrix_Free(M);
Matrix_Free(Ct);
return Peqs;
} /* Polyhedron_Remove_parm_eqs */
/** extracts the equalities involving the parameters only, try to introduce
them back and compare the two polyhedra.
Reads a polyhedron and a context.
*/
int test_Constraints_Remove_parm_eqs(Matrix * A, Matrix * B) {
int isOk = 1;
Matrix * M, *C, *Cp, * Eqs, *M1, *C1;
Polyhedron *Pm, *Pc, *Pcp, *Peqs, *Pint;
unsigned int * elimParms;
printf("----- test_Constraints_Remove_parm_eqs() -----\n");
M1 = Matrix_Copy(A);
C1 = Matrix_Copy(B);
M = Matrix_Copy(M1);
C = Matrix_Copy(C1);
/* compute the combined polyhedron */
Pm = Constraints2Polyhedron(M, maxRays);
Pc = Constraints2Polyhedron(C, maxRays);
Pcp = align_context(Pc, Pm->Dimension, maxRays);
Polyhedron_Free(Pc);
Pc = DomainIntersection(Pm, Pcp, maxRays);
Polyhedron_Free(Pm);
Polyhedron_Free(Pcp);
Matrix_Free(M);
Matrix_Free(C);
/* extract the parm-equalities, expressed in the combined space */
Eqs = Constraints_Remove_parm_eqs(&M1, &C1, 1, &elimParms);
printf("Removed equalities: \n");
show_matrix(Eqs);
printf("Polyhedron without equalities involving only parameters: \n");
show_matrix(M1);
printf("Context without equalities: \n");
show_matrix(C1);
/* compute the supposedly-same polyhedron, using the extracted equalities */
Pm = Constraints2Polyhedron(M1, maxRays);
Pcp = Constraints2Polyhedron(C1, maxRays);
Peqs = align_context(Pcp, Pm->Dimension, maxRays);
Polyhedron_Free(Pcp);
Pcp = DomainIntersection(Pm, Peqs, maxRays);
Polyhedron_Free(Peqs);
Polyhedron_Free(Pm);
Peqs = Constraints2Polyhedron(Eqs, maxRays);
Matrix_Free(Eqs);
Matrix_Free(M1);
Matrix_Free(C1);
Pint = DomainIntersection(Pcp, Peqs, maxRays);
Polyhedron_Free(Pcp);
Polyhedron_Free(Peqs);
/* test their equality */
if (!PolyhedronIncludes(Pint, Pc)) {
isOk = 0;
}
else {
if (!PolyhedronIncludes(Pc, Pint)) {
isOk = 0;
}
}
Polyhedron_Free(Pc);
Polyhedron_Free(Pint);
return isOk;
} /* test_Constraints_Remove_parm_eqs() */
