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SRdeformations :: newEmptyComplex

newEmptyComplex -- Generates an empty complex.

Synopsis

Description

Generates an empty complex. Face and facet data or just facet data can be added later by addFaceDataToComplex or addFacetDataToComplex.

This function is mainly used internally to create an empty complex data structure to be filled later, but may occasionally be useful to the user and is hence exported.

i1 : R=QQ[x_0..x_4]

o1 = R

o1 : PolynomialRing
i2 : addCokerGrading(R)

o2 = | -1 -1 -1 -1 |
     | 1  0  0  0  |
     | 0  1  0  0  |
     | 0  0  1  0  |
     | 0  0  0  1  |

              5        4
o2 : Matrix ZZ  <--- ZZ
i3 : I=ideal(x_0*x_1,x_1*x_2,x_2*x_3,x_3*x_4,x_4*x_0)

o3 = ideal (x x , x x , x x , x x , x x )
             0 1   1 2   2 3   3 4   0 4

o3 : Ideal of R
i4 : C=idealToComplex(I)

o4 = 1: x x  x x  x x  x x  x x  
         0 2  0 3  1 3  1 4  2 4

o4 : complex of dim 1 embedded in dim 4 (printing facets)
     equidimensional, simplicial, F-vector {1, 5, 5, 0, 0, 0}, Euler = -1
i5 : Cl=newEmptyComplex(R)

o5 = empty complex

o5 : complex of dim -1 embedded in dim 4 (printing facets)
     equidimensional, simplicial
i6 : addFacetDataToComplex(Cl,facets C)

o6 = done
i7 : Cl==C

o7 = true

See also

Ways to use newEmptyComplex :