[GiNaC-list] About non commutative transformations in GiNaC
abpetrov
abpetrov at ufacom.ru
Tue Jan 24 20:21:11 CET 2017
It works.
Thank you for your answer.
But important question remains.
Can I get latex output for a and ap like
a^{- i_1 ... i_n}_{j_1 ... j_n} with contravariant and covariant indexes?
For ncsymbol class I can do it.
When I tried to do it with clifford with program
cout << latex << endl;
cout << indexed(a,nu) << endl;
I got next result:
{\clifford[0]{e}_{{0} }}_{{\nu} }
It contains excess symbols like {\clifford[0]{e}_{{0} }} and don't
contains a^{-} or a^{+}
On 01/23/2017 03:32 PM, Vladimir V. Kisil wrote:
> Hi,
>
>>>>>> On Mon, 23 Jan 2017 00:35:56 +0500, abpetrov <abpetrov at ufacom.ru> said:
> ABP> Below is simple example of program with program output. How to
> ABP> change the class ncsymbol so that it was possible to apply
> ABP> rules like a*ap==ap*a+1?
>
> If you need just an implementation of the Heisenberg commutation
> relations you can use clifford class for this. GiNaC clifford class
> can handle both anti-commutators (proper Clifford algebras) and
> commutators. The attached example show this: "+1" at the end of
> definition of e tells to use commutators.
>
> Many years ago I derived a class lie_algebra from the class clifford,
> it was able to represent an arbitrary Lie algebra. At that time it was
> badly written (messing with some pointers) and it does not work with
> the current GiNaC (as I have discovered yesterday). Yet, that can be
> done properly. However, the speed for large commutators was not great,
> Singular is doing this much better.
>
> Best wishes,
> Vladimir
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