Let G be plane curve of degree 9 with 4 triple, 5 ordinary double points which contains k<5 points among the ninth fixed points of the pencil of cubics through the 4 triple points, and and 4 chosen double points by omitting one of them. This function compute the list of ideals of the k scrolls which are swept out by the g16 ’s induced from the pencil of cubics.
i1 : p=nextPrime 10^4; -- a prime number |
i2 : time L=random6gonalGenus11CurvekPencil(p,9);
-- used 2.63053 seconds
|
i3 : time S=scrollPencilOfCubicsFixedPoints(L);
-- used 5.21104 seconds
|
i4 : ScrollBetti=apply(S,s->betti res s)
0 1 2 3 4 5 0 1 2 3 4 5 0 1 2 3 4 5
o4 = {total: 1 15 40 45 24 5, total: 1 15 40 45 24 5, total: 1 15 40 45 24 5,
0: 1 . . . . . 0: 1 . . . . . 0: 1 . . . . .
1: . 15 40 45 24 5 1: . 15 40 45 24 5 1: . 15 40 45 24 5
------------------------------------------------------------------------
0 1 2 3 4 5
total: 1 15 40 45 24 5}
0: 1 . . . . .
1: . 15 40 45 24 5
o4 : List
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