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Macaulay2Doc :: newRing

newRing -- make a copy of a ring, with some features changed

Synopsis

Description

If a different number of variables is given with Variables, then the list of degrees in R will be ignored. If a new degree rank is specified with DegreeRank then the list of degrees and the heft vector of R will be ignored. If a new nonempty list of degrees is specified with Degrees, then the degree rank and and the heft vector of R will be ignored.

i1 : R = QQ[x,y,MonomialOrder => Lex,Degrees=>{3,5}];
i2 : describe newRing(R,MonomialOrder => GRevLex)

o2 = QQ[x..y, Degrees => {3, 5}, Heft => {1}, MonomialOrder => {MonomialSize => 32}, DegreeRank => 1]
                                                               {GRevLex => {3, 5} }
                                                               {Position => Up    }
i3 : describe newRing(R,Variables=>4)

o3 = QQ[p ..p , Degrees => {4:1}, Heft => {1}, MonomialOrder => {MonomialSize => 32}, DegreeRank => 1]
         0   3                                                  {Lex => 2          }
                                                                {Position => Up    }
                                                                {GRevLex => {2:1}  }
i4 : describe newRing(R,Heft=>{2})

o4 = QQ[x..y, Degrees => {3, 5}, Heft => {2}, MonomialOrder => {MonomialSize => 32}, DegreeRank => 1]
                                                               {Lex => 2          }
                                                               {Position => Up    }
i5 : S = R/(x^2+y^3);
i6 : describe newRing(R,Variables=>2)

o6 = QQ[p ..p , Degrees => {3, 5}, Heft => {1}, MonomialOrder => {MonomialSize => 32}, DegreeRank => 1]
         0   1                                                   {Lex => 2          }
                                                                 {Position => Up    }

The default values for the options of newRing are all set to a non-accessible private symbol whose name is nothing.

Ways to use newRing :