Hello again! I have followed your instructions and come up with the following:
X = simplicial_complexes.Torus() C = X.chain_complex(cochain=True) print C._chomp_repr_() H = C.homology(generators=True) gen1 = H[1][1][0] gen2 = H[1][1][1] d1 = C.differential()[1] This works very well so far. In particular d1*gen1 gives the zero vector as it should. Now: How can I get the bijection between the indices of the vectors gen1 and gen2 and the corresponding 1-faces in X? C._chomp_repr_() gives the boundary matrices in the form: dimension 1 boundary a1 = - 1 * a3 - 1 * a10 boundary a2 = - 1 * a2 - 1 * a5 boundary a3 = + 1 * a4 + 1 * a9 boundary a4 = + 1 * a6 + 1 * a12 boundary a5 = + 1 * a2 + 1 * a11 boundary a6 = - 1 * a4 - 1 * a11 boundary a7 = + 1 * a4 + 1 * a8 boundary a8 = + 1 * a5 + 1 * a14 boundary a9 = - 1 * a9 + 1 * a10 boundary a10 = + 1 * a1 + 1 * a6 boundary a11 = - 1 * a6 - 1 * a8 boundary a12 = + 1 * a5 + 1 * a7 boundary a13 = + 1 * a8 + 1 * a14 boundary a14 = + 1 * a7 + 1 * a9 ... But I don't see any information what face, say, a1 corresponds to. Am I missing something? Thank you very much for your help! Felix -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org