construct QuadraticForm and BinaryQF objects from polynomial

[yyyyx4]

QuadraticForm and BinaryQF objects have a .polynomial() method to return the quadratic form represented as a multivariate polynomial, but the converse is not currently available. This patch adds it.

Component: quadratic forms

Author: Lorenz Panny

Branch/Commit: 9224d7e

Reviewer: Matthias Koeppe

Issue created by migration from https://trac.sagemath.org/ticket/34863

[sagetrac-git]

Changed commit from 87c8658 to a3a94c0

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

a3a94c0

also implement .from_polynomial() for BinaryQF

[mkoeppe]

comment:3

+        Construct a :class:`BinaryQF` from a bivariate polynomial
+        with integer coefficients. Converse of :meth:`polynomial`.

I think that should be "inverse"

[mkoeppe]

Reviewer: Matthias Koeppe

[mkoeppe]

comment:4

Other than that, LGTM.

[sagetrac-git]

Changed commit from a3a94c0 to 9224d7e

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

9224d7e

converse -> inverse

[yyyyx4]

comment:6

Thanks! Changed the word and setting to positive review under the assumption that that's what your comment:4 meant.

[vbraun]

Changed branch from public/construct_quadratic_form_from_polynomial to 9224d7e