It works for me in Sage 4.3.3 and in 4.4.2. ---------------------------------------------------------------------- | Sage Version 4.3.3, Release Date: 2010-02-21 | | Type notebook() for the GUI, and license() for information. | ---------------------------------------------------------------------- sage: basering = PolynomialRing(SR, 'x') sage: polynomial = basering.lagrange_polynomial([(0,0), (1,pi), (2, pi/ ....: 2)]) sage: polynomial -3/4*pi*x^2 + 7/4*pi*x
Matthias Meulien wrote: > Hi, > > I can't figure out why the following commands ends with a TypeError > exception. > > sage: basering = PolynomialRing(SR, 'x') > sage: polynomial = basering.lagrange_polynomial([(0,0), (1,pi), (2, pi/ > 2)]) > sage: > polynomial.base_ring() > Symbolic Ring > sage: > type(polynomial) > <class > 'sage.rings.polynomial.polynomial_element_generic.Polynomial_generic_dense_field'> > sage: > polynomial.roots(x) > --------------------------------------------------------------------------- > TypeError Traceback (most recent call > last) > > /home/matthias/<ipython console> in <module>() > > /home/matthias/Sources/sage-4.3.5/local/lib/python2.6/site-packages/ > sage/rings/polynomial/polynomial_element.so in > sage.rings.polynomial.polynomial_element.Polynomial.roots (sage/rings/ > polynomial/polynomial_element.c:29945)() > > /home/matthias/Sources/sage-4.3.5/local/lib/python2.6/site-packages/ > sage/rings/polynomial/polynomial_element.so in > sage.rings.polynomial.polynomial_element.Polynomial.change_ring (sage/ > rings/polynomial/polynomial_element.c:15968)() > > /home/matthias/Sources/sage-4.3.5/local/lib/python2.6/site-packages/ > sage/rings/polynomial/polynomial_ring.pyc in change_ring(self, R) > 606 from sage.rings.polynomial.polynomial_ring_constructor > import PolynomialRing > 607 > --> 608 return PolynomialRing(R, names=self.variable_name(), > sparse=self.is_sparse()) > 609 > 610 def change_var(self, var): > > /home/matthias/Sources/sage-4.3.5/local/lib/python2.6/site-packages/ > sage/rings/polynomial/polynomial_ring_constructor.pyc in > PolynomialRing(base_ring, arg1, arg2, sparse, order, names, name, > implementation) > 317 > 318 if not m.ring.is_Ring(base_ring): > --> 319 raise TypeError, 'base_ring must be a ring' > 320 > 321 if arg1 is None: > > TypeError: base_ring must be a ring > > Thanks for reading. > -- 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
