Re: [Maxima-discuss] sign of permutation

[Daniel V. <dan...@ya...>]

 Hi Jaime,
Thank you for the input.However, this is not what I need.
My original intention was to symmetrize or anti-symmetrize tensors with abstract indices.For the symmetrization there is no problem because you sum all the permutations.But for the anti-symmetrization you need to sum all the permutations but each oneshould be multiplied by the sign (or parity) of the permutation.
perm_parity([λ,σ,μ]) issues an error: "argument should be a permutation".
Thanks,
Daniel Volinski

    En viernes, 5 de mayo de 2023, 21:23:23 GMT+3, Jaime Villate <vi...@fe...> escribió:  
 
 On 05/05/23 18:24, Daniel Volinski via Maxima-discuss wrote:
> Is there a command in Maxima the calculates the sign of a permutation?
>
> Given a base permutation (a list) and a test permutation (a list) of 
> the same elements,
> I would l like a command to calculate the number of switches needed to 
> go from one
> to the other or (alternatively) whether this number is odd or even.
>
Hello Daniel,

Function perm_parity, from additional package combinatorics, will give 0 
if the permutation is even or 1 if it is odd.

Regards,

Jaime