The example here https://sagemanifolds.obspm.fr/examples.html of
> Electromagnetism in Minkowski spacetime > <https://nbviewer.jupyter.org/github/ernestyalumni/Gravite/blob/master/EMsage.ipynb> > [ipynb > <https://raw.githubusercontent.com/ernestyalumni/Gravite/master/EMsage.ipynb>] > (Electromagnetic field 2-form from E and B, Maxwell equations, conserved > current, Lorentz force, Poynting vector) Fails with the error in the title and in more detail below. I created a MWE. I presume this worked at some point but how do I get the exterior derivative of a 1-form in the latest release of sage manifolds? > M = Manifold(4, 'M', latex_name=r'\mathcal{M}', structure='Lorentzian') > BL.<t,x,y,z> = M.chart(r"t x y z") > var('E_x E_y E_z') > dt, dx, dy, dz = BL.coframe()[:] > E = E_x * dx + E_y * dy + E_z * dz > E.set_name('E') > (E.wedge(BL.coframe()[0])).exterior_der() fails with > --------------------------------------------------------------------------- > AttributeError Traceback (most recent call last) > Cell In [66], line 1 > ----> 1 (E.wedge(BL.coframe()[Integer(0)])).exterior_der() > > File > /private/var/tmp/sage-10.1-current/local/var/lib/sage/venv-python3.11.1/lib/python3.11/site-packages/sage/structure/element.pyx:488, > in sage.structure.element.Element.__getattr__ > (build/cythonized/sage/structure/element.c:4846)() > 486 AttributeError: > 'LeftZeroSemigroup_with_category.element_class' object has no attribute > 'blah_blah' > 487 """ > --> 488 return self.getattr_from_category(name) > 489 > 490 cdef getattr_from_category(self, name): > > File > /private/var/tmp/sage-10.1-current/local/var/lib/sage/venv-python3.11.1/lib/python3.11/site-packages/sage/structure/element.pyx:501, > in sage.structure.element.Element.getattr_from_category > (build/cythonized/sage/structure/element.c:4958)() > 499 else: > 500 cls = P._abstract_element_class > --> 501 return getattr_from_other_class(self, cls, name) > 502 > 503 def __dir__(self): > > File > /private/var/tmp/sage-10.1-current/local/var/lib/sage/venv-python3.11.1/lib/python3.11/site-packages/sage/cpython/getattr.pyx:357, > in sage.cpython.getattr.getattr_from_other_class > (build/cythonized/sage/cpython/getattr.c:2706)() > 355 dummy_error_message.cls = type(self) > 356 dummy_error_message.name = name > --> 357 raise AttributeError(dummy_error_message) > 358 cdef PyObject* attr = instance_getattr(cls, name) > 359 if attr is NULL: > > AttributeError: 'DiffFormFreeModule_with_category.element_class' object has > no attribute 'exterior_der' -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/sage-support/4A450800-F1F1-444D-A289-3EB8C09018C1%40gmail.com.
