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D.13.3.29 hashesToFan
Procedure from library gitfan.lib (see gitfan_lib).
- Usage:
- hashesToFan(hashes, OC): hashes list of bigint, OC list of cones.
- Assume:
- the elements of OC are the orbit cones used in the hash representation of the GIT cones.
- Return:
- a fan, with maximal cones the intersections of the cones in OC according to the binary representation of the hashes.
Example:
| | LIB "gitfan.lib";
setcores(4);
==> 4
ring R = 0,T(1..10),wp(1,1,1,1,1,1,1,1,1,1);
ideal J =
T(5)*T(10)-T(6)*T(9)+T(7)*T(8),
T(1)*T(9)-T(2)*T(7)+T(4)*T(5),
T(1)*T(8)-T(2)*T(6)+T(3)*T(5),
T(1)*T(10)-T(3)*T(7)+T(4)*T(6),
T(2)*T(10)-T(3)*T(9)+T(4)*T(8);
intmat Q[5][10] =
1, 1, 1, 1, 0, 0, 0, 0, 0, 0,
1, 0, 0, 0, 1, 1, 1, 0, 0, 0,
0, 1, 1, 0, 0, 0, -1, 1, 0, 0,
0, 1, 0, 1, 0, -1, 0, 0, 1, 0,
0, 0, 1, 1, -1, 0, 0, 0, 0, 1;
list AF= afaces(J,nrows(Q));
AF=fullDimImages(AF,Q);
AF = minimalAfaces(AF);
list OC = orbitCones(AF,Q);
cone Qgamma = coneViaPoints(transpose(Q));
list GIT = GITfanParallel(OC,Q,Qgamma);
fan Sigma = hashesToFan(GIT,OC);
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