Ondrej Certik wrote: > Hi Comer, > > On Wed, Mar 18, 2009 at 9:17 AM, [email protected] > <[email protected]> wrote: > >> I am interested in using Sympy but see on the web page that >> implementing tensors is rather low on the list of interested >> additional features. Can the developers give some indication as to >> when tensor algebra will be added to Sympy? >> > > When we find someone interested in pushing this forward. If you'd be > interested, play with some very preliminary code here: > > $ python examples/advanced/relativity.py > [...] > solve the Einstein's equations: > ⎛ C₂⎞ > λ(r) = -log⎜C₁ + ──⎟ > ⎝ r ⎠ > metric: > ⎡ C₂ ⎤ > ⎢-C₁ - ── 0 0 0 ⎥ > ⎢ r ⎥ > ⎢ ⎥ > ⎢ 1 ⎥ > ⎢ 0 ─────── 0 0 ⎥ > ⎢ C₂ ⎥ > ⎢ C₁ + ── ⎥ > ⎢ r ⎥ > ⎢ ⎥ > ⎢ 2 ⎥ > ⎢ 0 0 r 0 ⎥ > ⎢ ⎥ > ⎢ 2 2 ⎥ > ⎣ 0 0 0 r ⋅sin (θ)⎦ > > > It allows you to calculate the Schwarzschild metrics pretty easily. > However, it'd be nice to polish the classes in there, and make it part > of sympy, write tests for it, more examples etc. If you'd be > interested in helping out, I fully support it. > > >> I do general relativity >> and thus need tensor capability. >> > > Yes, I would love to do more advanced stuff in GR as well with sympy. > > Ondrej > > > > > If you get the latest snapshot of sympy:
git clone git://git.sympy.org/sympy.git There is an extensive geometric algebra/calculus module (numpy required) with attached documentation (python-sphinx and dvipng required). The use of geometric algebra in general relativity is documented in "Geometric Algebra for Physicists" by Doran and Lasenby (Cambridge University Press). The main website is http://www.mrao.cam.ac.uk/~clifford/. One of the examples in the book is a one line expression of the curvature tensor for a rotating black hole using geometric algebra. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/sympy?hl=en -~----------~----~----~----~------~----~------~--~---
