So would these mean starting afresh or just adding more to the present system. And my idea is the matrix transforms method between various co ordinate systems which would be applied to covariant and contravariant co ordinates.I have been working on this stream of ideas and would also like to add the testing of basis and span if possible.One more question can this be implemented as a project during summer.Thanks.
On Wed, Apr 24, 2013 at 12:54 AM, Stefan Krastanov < krastanov.ste...@gmail.com> wrote: > These > > "covariant and contravariant co ordinate systems" > "moving through different co ordinate systems" > "index-contraction system" > > can mean a lot of different things in the context of a CAS. Some of > them are already implemented in sympy or numpy. For instance: > > 1. naive index contraction: > > - naive index contraction is implemented in numpy.einsum and can be > used with sympy through the dtype=object. > - you can do naive index contraction also through the `tensor` module > in sympy, but it is destined to be used solely for code generation of > loops over n-dim arrays. > > 2. Actual tensor objects (i.e. geometrical objects) are implemented in > various ways in sympy: > > - the very new. very fast and very shiny tensor canonicalization > routines contributed by Pernici (for the xAct style of work, not yes > supporting explicit tensors) > > - for differential geometry see the `diffgeom` module: it is > coordinate system independent in the meaning that you write down your > objects explicitly in some coordinate systems, but you can mix > together bases and switch from one to another on-the-fly. > > Please contribute to and clean up these modules, before you start > adding routines that are already partially implemented. > > On 23 April 2013 21:03, F. B. <franz.bona...@gmail.com> wrote: > > I started working on such an implementation yesterday. It has already an > > index-contraction system. Give me some days to finish it, then I'll post > it. > > > > This part is not only helpful, it is ESSENTIAL to all modern physics! > > > > > > On Tuesday, April 23, 2013 8:52:40 PM UTC+2, Amit wrote: > >> > >> Can the tensor implimentation related to covariant and contravariant co > >> ordinate systems and moving through different co ordinate systems be > >> helpful.I mean to say could covariant and contravariant transforms form > the > >> basis for tensor module.Thanks. > > > > -- > > You received this message because you are subscribed to the Google Groups > > "sympy" group. > > To unsubscribe from this group and stop receiving emails from it, send an > > email to sympy+unsubscr...@googlegroups.com. > > To post to this group, send email to sympy@googlegroups.com. > > Visit this group at http://groups.google.com/group/sympy?hl=en-US. > > For more options, visit https://groups.google.com/groups/opt_out. > > > > > > -- > You received this message because you are subscribed to the Google Groups > "sympy" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to sympy+unsubscr...@googlegroups.com. > To post to this group, send email to sympy@googlegroups.com. > Visit this group at http://groups.google.com/group/sympy?hl=en-US. > For more options, visit https://groups.google.com/groups/opt_out. > > > -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sympy+unsubscr...@googlegroups.com. To post to this group, send email to sympy@googlegroups.com. Visit this group at http://groups.google.com/group/sympy?hl=en-US. For more options, visit https://groups.google.com/groups/opt_out.
