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coefficientRing(SimplicialComplex) -- get the coefficient ring

Synopsis

Description

i1 : loadPackage "SimplicialComplexes";
i2 : R = QQ[a..d];
i3 : D = simplicialComplex monomialIdeal(a*b*c*d);
i4 : ring D

o4 = R

o4 : PolynomialRing
i5 : coefficientRing D

o5 = QQ

o5 : Ring
i6 : S = ZZ[w..z];
i7 : E = simplicialComplex monomialIdeal(w*x*y*z);
i8 : ring E

o8 = S

o8 : PolynomialRing
i9 : coefficientRing E

o9 = ZZ

o9 : Ring
Some computations depend on the choice of coefficient ring, for example, the boundary maps and the chain complex of D.
i10 : chainComplex D

        1       4       6       4
o10 = QQ  <-- QQ  <-- QQ  <-- QQ
                               
      -1      0       1       2

o10 : ChainComplex
i11 : chainComplex E

        1       4       6       4
o11 = ZZ  <-- ZZ  <-- ZZ  <-- ZZ
                               
      -1      0       1       2

o11 : ChainComplex

See also