Method removeRedundantRows

gfanlib/gfanlib_zcone.cpp:386–450

    return normals;
  }
  void removeRedundantRows(ZMatrix &inequalities, ZMatrix &equations, bool removeInequalityRedundancies)
  {
          ensureCddInitialisation();

    int numberOfEqualities=equations.getHeight();
    int numberOfInequalities=inequalities.getHeight();
    int numberOfRows=numberOfEqualities+numberOfInequalities;

    if(numberOfRows==0)return;//the full space, so description is already irredundant

    // dd_rowset r=NULL;
    ZMatrix g=inequalities;
    g.append(equations);

    // dd_LPSolverType solver=dd_DualSimplex;
    dd_MatrixPtr A=NULL;
    dd_ErrorType err=dd_NoError;

    A=ZMatrix2MatrixGmp(g,&err);
    if (err!=dd_NoError) goto _L99;

    for(int i=numberOfInequalities;i<numberOfRows;i++)
      set_addelem(A->linset,i+1);

    A->objective=dd_LPmax;

    dd_rowset impl_linset;
    dd_rowset redset;
    dd_rowindex newpos;

    if(removeInequalityRedundancies)
      dd_MatrixCanonicalize(&A, &impl_linset, &redset, &newpos, &err);
    else
      dd_MatrixCanonicalizeLinearity(&A, &impl_linset, &newpos, &err);

    if (err!=dd_NoError) goto _L99;

    {
      int n=A->colsize-1;
      equations=ZMatrix(0,n);     //TODO: the number of rows needed is actually known
      inequalities=ZMatrix(0,n);  //is known by set_card(). That might save some copying.

      {
        int rowsize=A->rowsize;
        QVector point(n);
        for(int i=0;i<rowsize;i++)
          {
            for(int j=0;j<n;j++)point[j]=Rational(A->matrix[i][j+1]);
            ((set_member(i+1,A->linset))?equations:inequalities).appendRow(QToZVectorPrimitive(point));
          }
      }
      assert(set_card(A->linset)==equations.getHeight());
      assert(A->rowsize==equations.getHeight()+inequalities.getHeight());

      set_free(impl_linset);
      if(removeInequalityRedundancies)
        set_free(redset);
      free(newpos);