In the first paragraph of the documentation it says: "If its dimension is denoted k then we typically store a basis of C as a kxn matrix, with rows the basis vectors. It is called the generator matrix of C."
I personally define a generator matrix to be a full rank matrix. I assumed that this was standard terminology. Is that assumption wrong? On Thu, Jun 9, 2011 at 5:52 PM, D. Monarres <dmmonar...@gmail.com> wrote: > > This also seems to cause problems with decoding. I am posting here just to > make sure that this would actually be considered a bug, not just user error. > Everything works as expected when I construct the same code with a full > rank generator matrix. > > > (with C defined as before) > > sage: C.decode([1,0,1,0,1]) > --------------------------------------------------------------------------- > IndexError Traceback (most recent call last) > /home/ayeq/sage/local/lib/python2.6/site-packages/sage/all_cmdline.pyc in > <module>() > /home/ayeq/sage/local/lib/python2.6/site-packages/sage/misc/decorators.pyc > in wrapper(*args, **kwds) > 571 kwds[new_name] = kwds[old_name] > 572 del kwds[old_name] > --> 573 return func(*args, **kwds) > 574 > 575 return wrapper > /home/ayeq/sage/local/lib/python2.6/site-packages/sage/coding/linear_code.pyc > in decode(self, right, algorithm) > 1174 from decoder import decode > 1175 if algorithm=="syndrome" or algorithm=="nearest neighbor": > -> 1176 return decode(self,right) > 1177 if not(algorithm in ["syndrome", "nearest > neighbor","guava"]): > 1178 raise NotImplementedError, "Only 'syndrome','nearest > neighbor','guava' are implemented." > /home/ayeq/sage/local/lib/python2.6/site-packages/sage/misc/decorators.pyc > in wrapper(*args, **kwds) > 571 kwds[new_name] = kwds[old_name] > 572 del kwds[old_name] > --> 573 return func(*args, **kwds) > 574 > 575 return wrapper > /home/ayeq/sage/local/lib/python2.6/site-packages/sage/coding/decoder.pyc in > decode(C, v, algorithm) > 119 return diffs[0][0]+v > 120 if algorithm=="syndrome": > --> 121 return -V(syndrome(C, v)[0])+v > 122 > 123 > /home/ayeq/sage/local/lib/python2.6/site-packages/sage/coding/decoder.pyc in > syndrome(C, v) > 45 v = v.list() > 46 v = V(v) > ---> 47 coset = [[c+v,hamming_weight(c+v)] for c in C] > 48 coset.sort(lambda x,y: x[1]-y[1]) > 49 return [x[0] for x in coset] > /home/ayeq/sage/local/lib/python2.6/site-packages/sage/coding/linear_code.pyc > in __iter__(self) > 759 k = self.dimension() > 760 F = self.base_ring() > --> 761 Cs,p = self.standard_form() > 762 Gs = Cs.gen_mat() > 763 V = VectorSpace(F,k) > /home/ayeq/sage/local/lib/python2.6/site-packages/sage/coding/linear_code.pyc > in standard_form(self) > 2438 for i in range(1,k+1): > 2439 r = M.rows()[i-1] > -> 2440 j = r.nonzero_positions()[0] > 2441 if (j < d and i <> j+1): > 2442 perm = perm *G([(i,j+1)]) > IndexError: list index out of range > > -- > To post to this group, send an email to sage-devel@googlegroups.com > To unsubscribe from this group, send an email to > sage-devel+unsubscr...@googlegroups.com > For more options, visit this group at > http://groups.google.com/group/sage-devel > URL: http://www.sagemath.org > -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
