ReconstructionFromComponentG1 fails for some examples

[edgarcosta]

> prec := 300;
> F := RationalsExtra(prec);
> R<x> := PolynomialRing(F);
> f := -204*x^6 - 1259*x^4 - 414*x^2 - 35;
> C := HyperellipticCurve(f);
> HeuristicEndomorphismRing(C);
Order of Associative Algebra of dimension 2 with base ring Rational Field
with coefficient ring Integer Ring
> HeuristicJacobianFactors(C);

HeuristicJacobianFactors(
X: Hyperelliptic Curve defined by y^2 = -204*x^6 - 1259*x^4 - 4...
)
ReconstructionFromComponent(
P: [-0.47434723226254522087260057717305449657073687586582307197...,
Q: [-0.47434723226254522087260057717305449657073687586582307197...,
mor: [* [1 0],  [1 1 0 0] [0 0 1 1] *]
)
ReconstructionFromComponentG1(
P: [-0.47434723226254522087260057717305449657073687586582307197...,
Q: [-3.02061536838249321515374768709301458213601516608650303035...,
mor: [* [1 0],  [1 1 0 0] [0 0 1 1] *]
)
In file "/Users/edgarcosta/projects/endomorphisms/endomorphisms/endomorphisms/magma/heuristic/DecCurves.m", line 30, column 1:
>> assert IsBigPeriodMatrix(Q);
   ^
Runtime error in assert: Assertion failed

[JRSijsling]

Fixed; checking for period matrix properties was done in an outdated way.