2024-01-03 10:34:04 +0200 received badge ● Popular Question (source) 2023-06-24 21:44:50 +0200 marked best answer Keep metric purely symbolic Is there an easy way to define a purely symbolic riemannian metric on a manifold? Or do I need to initialize it like this g[0,0] = function('g00')(t,x,y,z) for example? 2023-06-24 21:44:40 +0200 marked best answer Why does sage fail to detect the symmetry here? M = Manifold(4, 'M') CM. = M.chart(r'u r:(0,+oo) θ:(0,pi) φ:(0,2*pi)') e = CM.coframe() du = e[0] dr = e[1] dθ = e[2] dφ = e[3] V = function('V') β = function('β') γ = function('γ') δ = function('δ') (dθ * dφ + dφ * dθ).symmetries() (dθ * dφ + dφ * dθ).symmetrize() == (dθ * dφ + dφ * dθ)  I want to define a (degenerate) metric:  g = M.metric('g') g.set(dθ * dφ + dφ * dθ)  this fails because Sage does not believe the tensor field to be symmetric. 2023-06-24 21:44:40 +0200 received badge ● Scholar (source) 2023-06-24 16:07:25 +0200 commented answer Why does sage fail to detect the symmetry here? Thanks, this works of course. Just find it odd that g.set(...) does not explicitly check that the argument is symmetric. 2023-06-24 00:56:41 +0200 asked a question Why does sage fail to detect the symmetry here? Why does sage fail to detect the symmetry here? M = Manifold(4, 'M') CM. = M.chart(r'u r:(0,+oo) θ:(0,pi) 2023-06-23 15:52:37 +0200 commented answer Keep metric purely symbolic oh, that is a pity. both in terms of writing it out and computationally. I will then use cadabra2 in the meantime for th 2023-06-23 15:32:46 +0200 received badge ● Supporter (source) 2023-06-23 14:03:08 +0200 asked a question Keep metric purely symbolic Keep metric purely symbolic Is there an easy way to define a purely symbolic riemannian metric on a manifold? Or do I ne 2022-08-15 15:15:27 +0200 received badge ● Student (source) 2022-08-15 12:27:50 +0200 asked a question Sage Manifolds: Asymptotically de Sitter Spacetime in Fefferman-Graham Gauge Sage Manifolds: Asymptotically de Sitter Spacetime in Fefferman-Graham Gauge I am new to the Sage Manifolds package and