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SRdeformations :: face

face -- Generate a face.

Synopsis

Description

Generate a Face F from a list L (or set S) of vertices. If the additional argument C is given it sets F.ofComplex=C to store the complex of which F is a face of.

If d and j are given then F.indices=d,j for storing the face dimension d and its index j in (F.ofComplex)#0.

i1 : R=QQ[x_0..x_4]

o1 = R

o1 : PolynomialRing
i2 : I=ideal(x_0*x_1,x_1*x_2,x_2*x_3,x_3*x_4,x_4*x_0)

o2 = ideal (x x , x x , x x , x x , x x )
             0 1   1 2   2 3   3 4   0 4

o2 : Ideal of R
i3 : C=idealToComplex I

o3 = 1: x x  x x  x x  x x  x x  
         0 2  0 3  1 3  1 4  2 4

o3 : complex of dim 1 embedded in dim 4 (printing facets)
     equidimensional, simplicial, F-vector {1, 5, 5, 0, 0, 0}, Euler = -1
i4 : F=C.fc_1_0

o4 = x x
      0 2

o4 : face with 2 vertices
i5 : F==face(vert F,C,1,0)

o5 = true

See also

Ways to use face :