On Wed, Jan 21, 2015 at 2:03 PM, Francesco Bonazzi <[email protected]> wrote:
> > > On Wednesday, January 21, 2015 at 8:12:31 PM UTC+1, [email protected] > wrote: >> >> Hi Francesco, >> >> I'm sorry for my long latency time. >> >> Concerning a Lie algebra defined by the structure constants: keep in mind >>> this is a way often used in Physics, which is not very rigorous. Structure >>> constants define an equivalence class of bases in a Lie algebra. >>> >>> For example, consider a Lie algebra with two generators: *A, B*. If you >>> define *X = 2*A - 3*B, Y = A + B*, then *X *and *Y* are still >>> generators, but will have generally different structure constants. >>> >> >> Yes, that is clear to me. Maybe the documentation is too imprecise at >> this point. Unfortunately a "real" Lie-Algebra class makes (except in the >> semisimple case) no sense, because the classification of Lie-Algebras is >> really a non-trivial problem. You may have a look on the method >> >> GLV_Action(self, a): #Computes the Action of an Element of GL(V) on the >> Variety of Structure Constants >> > > By the way, there is already some support for Lie algebras in SymPy: > > > https://github.com/sympy/sympy/tree/998a9100f3c8493a2b6f1ff10c02024f36d48811/sympy/liealgebras > > Have a look at this. It does not depend on numpy. Also notice where the > tests are placed. > > >> Due to your other remarks, I will revise my code promptly. >> >> > Actually, those remarks are necessary if you want your objects to be part > of a SymPy expression tree. There are some exceptions in SymPy where > classes do not inherit from Basic, but those objects are not meant to be > part of the expression tree. > > Concerning the style, usually in SymPy class names use CamelCase, while > methods and functions use snake_case. > We follow PEP 8 style, which is the style for all Python (not just SymPy). Though note that we do break PEP 8 sometimes (e.g., for mathematical functions, we don't always use these case conventions, for instance sin() is a class but we still use lowercase because that's how the mathematical function is spelled). In this case, I would always keep things like gl/GL capitalized according to the mathematical conventions. Aaron Meurer > -- > 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 [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/sympy. > To view this discussion on the web visit > https://groups.google.com/d/msgid/sympy/239c3826-c4cc-41c2-a7d5-d936363a630d%40googlegroups.com > <https://groups.google.com/d/msgid/sympy/239c3826-c4cc-41c2-a7d5-d936363a630d%40googlegroups.com?utm_medium=email&utm_source=footer> > . > > For more options, visit https://groups.google.com/d/optout. > -- 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 [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/CAKgW%3D6%2BEiBN27q1oTtGJK_-i6%3DiXgOA6WKXnRSdpbnA2voSwRQ%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
