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.
