Further followup: I think I located the problem in p1list affecting issue 1. See trac #20932 for additional discussion.
On Sunday, July 3, 2016 at 9:31:20 AM UTC-7, Kiran Kedlaya wrote: > > Following up on issue 1: > > On Saturday, July 2, 2016 at 9:42:53 PM UTC-7, Rob Harron wrote: >> >> sage: chi = kronecker_character(3*34603) >> sage: M = ModularSymbols(chi, 2, sign=1, base_ring=GF(3)) >> ... >> File >> "/projects/sage/sage-6.10/local/lib/python2.7/site-packages/sage/modular/modsym/relation_matrix.py", >> >> line 126, in modS_relations >> assert j != -1 >> AssertionError >> >> > Inspecting the traceback suggests that the issue is here: > > sage: chi = kronecker_character(3*34603) > sage: from sage.modular.modsym.manin_symbol_list import > ManinSymbolList_character > sage: m = ManinSymbolList_character(chi,2); m > > Manin Symbol List of weight 2 for Gamma1(103809) with character [-1, -1] > > sage: for i in range(len(m)): > sage: j, s = m.apply_S(i) > sage: if not j != -1: print i, j, s #should print nothing > > 34604 -1 0 > 69207 -1 0 > 126878 -1 0 > > > That value of j appears to be the index of some tuple in the underlying list > of m; an index of -1 means "not found". This suggests that the list of Manin > symbols is not being generated correctly for some reason. > > > That generation happens in the file src/sage/modular/modsym/p1list.pyx. Here > is a test that seems to isolate the issue: > > > sage: import sage.modular.modsym.p1list as p1list > sage: for (i,j) in p1list.P1List(103809): > sage: if i != 1 and i != 3: print (i,j) > > (0, 1) #should also return (34603, 1) and (34603, 2). > > > There seems to be a cutover above level 46340, which might be exposing some > poorly tested legacy code. > > > I'm not sure whether the other issue is related, but it does appear to be in > the same file, so I wouldn't rule it out. > > > Kiran > > > > -- You received this message because you are subscribed to the Google Groups "sage-nt" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send an email to [email protected]. Visit this group at https://groups.google.com/group/sage-nt. For more options, visit https://groups.google.com/d/optout.
