Fibration hop functionality #2715
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| @assert F === parent(x1) "something is wrong with caching of fraction fields" | ||
| # TODO: eventually add the inverse. | ||
| trans = MapFromFunc(F, F, f->evaluate(numerator(f), [x1, y1])//evaluate(denominator(f), [x1, y1])) | ||
| return trans(F(g)), trans |
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Here we actually care about the factor of F(g) which is in weierstrass form.
So you would
- factor
numerator(F(g)) - get the factor h of g which is in weierstrass form and discard the other factors.
- Return h, trans
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How do we find the factor in Weierstrass form? I just extrapolated from our vinberg script here. Is this 100% mandatory what your write here?
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I would say that we look at its monomials and make sure that they
contain [y^2, x^3] and are all contained in [y^2, x*y, y, x^3, x^2, x, 1].
Yes, I would say that it is 95% mandatory. Because otherwise we will have to fish it out by hand each time and cannot automatize anything or fish it out later in the automatization. This seems like the best place for fishing for the (long) weierstrass equation.
Codecov Report
Additional details and impacted files@@ Coverage Diff @@
## master #2715 +/- ##
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- Coverage 72.72% 72.69% -0.04%
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Files 443 444 +1
Lines 63107 63348 +241
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+ Hits 45896 46049 +153
- Misses 17211 17299 +88
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Tests will need to be adjusted to the new names too. |
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Could you please add a test for each method over a function field? Just to make sure it runs and we do not need to fix it later. Because that is where we will actually use it. |
I add some ported functionality for @simonbrandhorst from earlier python scripts.