Hello, Ursula Whitcher <urs...@yarntheory.net> wrote:
> Asking Sage to compute the cardinality of point sets of projective > varieties over finite fields produces an infinite recursion error. > This is weird, since the count_points() function works just fine > (albeit slowly) in this situation. This is very likely the bug reported at <https://trac.sagemath.org/ticket/18400>. Peter > Here's an example. > Entering: > F = FiniteField(37) > P3.<x,y,z,w> = ProjectiveSpace(3,F) > P3.point_set().cardinality() > yields an error that begins: > Error in lines 3-3 Traceback (most recent call last): File > "/projects/sage/sage-7.3/local/lib/python2.7/site-packages/smc_sagews/sage_server.py", > line 976, in execute exec compile(block+'\n', '', 'single') in namespace, > locals File "", line 1, in <module> File > "/projects/sage/sage-7.3/local/lib/python2.7/site-packages/sage/schemes/generic/homset.py", > line 584, in cardinality return sum(ZZ.one() for point in self) File > "/projects/sage/sage-7.3/local/lib/python2.7/site-packages/sage/schemes/generic/homset.py", > line 584, in <genexpr> return sum(ZZ.one() for point in self) File > "sage/structure/parent.pyx", line 1596, in > sage.structure.parent.Parent.__getitem__ > (/projects/sage/sage-7.3/src/build/cythonized/sage/structure/parent.c:12913) > return self.list()[n] File > "/projects/sage/sage-7.3/local/lib/python2.7/site-packages/sage/schemes/generic/homset.py", > line 602, in list return tuple(self) File > "/projects/sage/sage-7.3/local/lib/python2.7/site-packages/sage/schemes/generic/homset.py", > line 584, in cardinality return sum(ZZ.one() for point in self) File > "/projects/sage/sage-7.3/local/lib/python2.7/site-packages/sage/schemes/generic/homset.py", > line 584, in <genexpr> return sum(ZZ.one() for point in self) File > "sage/structure/parent.pyx", line 1596, in > sage.structure.parent.Parent.__getitem__ > (/projects/sage/sage-7.3/src/build/cythonized/sage/structure/parent.c:12913) > return self.list()[n] > continues looping for a while, and ends: > File "sage/structure/parent.pyx", line 1596, in > sage.structure.parent.Parent.__getitem__ > (/projects/sage/sage-7.3/src/build/cythonized/sage/structure/parent.c:12913) > return self.list()[n] File > "/projects/sage/sage-7.3/local/lib/python2.7/site-packages/sage/schemes/generic/homset.py", > line 602, in list return tuple(self) File > "/projects/sage/sage-7.3/local/lib/python2.7/site-packages/sage/schemes/generic/homset.py", > line 584, in cardinality return sum(ZZ.one() for point in self) File > "/projects/sage/sage-7.3/local/lib/python2.7/site-packages/sage/schemes/generic/homset.py", > line 584, in <genexpr> return sum(ZZ.one() for point in self) File > "sage/structure/parent.pyx", line 1590, in > sage.structure.parent.Parent.__getitem__ > (/projects/sage/sage-7.3/src/build/cythonized/sage/structure/parent.c:12742) > meth = getattr_from_other_class(self, self._category.parent_class, > '__getitem__') File "sage/structure/misc.pyx", line 250, in > sage.structure.misc.getattr_from_other_class > (/projects/sage/sage-7.3/src/build/cythonized/sage/structure/misc.c:1731) > if isinstance(self, cls): RuntimeError: maximum recursion depth exceeded > while calling a Python object > On the other hand, > P3.count_points(1) > returns [52060]. > --Ursula. > > -- > You received this message because you are subscribed to the Google Groups > "sage-devel" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to sage-devel+unsubscr...@googlegroups.com. > To post to this group, send email to sage-devel@googlegroups.com. > Visit this group at https://groups.google.com/group/sage-devel. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at https://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
