One can easily calculate the intersection of a lattice with a linear subspace of QQ^n:
sage: V = VectorSpace(QQ,3) sage: L = ZZ^3 sage: U = V.subspace([(1,1,0), (0,1,1)]) sage: L.intersection(U) Free module of degree 3 and rank 2 over Integer Ring Echelon basis matrix: [ 1 0 -1] [ 0 1 1]
If I try to calculate the intersection of an affine subspace and a lattice in the same way, I get an error message:
sage: from sage.geometry.hyperplane_arrangement.affine_subspace import AffineSubspace sage: A = AffineSubspace((1,0,0), U) sage: L.intersection(A) --------------------------------------------------------------------------- TypeError Traceback (most recent call last) <ipython-input-40-6458203faea4> in <module>() ----> 1 L.intersection(A) [...] TypeError: other must be a free module
Is there another way to do this?
