The easiest way is to define a Function subclass that sorts the arguments.
class F(Function):
@classmethod
def eval(cls, x, y):
if default_sort_key(x) > default_sort_key(y):
return cls(y, x)
For more than two variables, I would use the algorithm described by Francesco.
Aaron Meurer
On Tue, Nov 14, 2017 at 10:13 AM, Francesco Bonazzi
<[email protected]> wrote:
> Not in the functions, but there is a symmetry canonicalization algorithm in
> the tensor module:
>
> http://docs.sympy.org/latest/modules/tensor/tensor.html
>
> Unfortunately it's unrelated.
>
> On Tuesday, 14 November 2017 05:35:07 UTC-5, danabe wrote:
>>
>> Hi all,
>> Is it possible to define a general symmetric function of two variables,
>> let's say F(x,y) such that F(x,y)-F(y,x) would evaluate to zero?
>> Thanks
>
>
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