The Solution class is indeed a good idea.
I think it would be best to have a unified data structure independent of the
number of solutions. The reason is that it is not clear from the outset how
many solutions an equation or system of equations will have. That is why I
think it would be better to have a list always or a dictionary always (or a
list of dictionaries always). The list of dictionaries idea is one of the
better ones, in my opinion.
Aaron Meurer
On Apr 20, 2011, at 3:57 AM, Alexey U. Gudchenko wrote:
> 20.04.2011 11:45, Chris Smith пишет:
>>> Solution class is needed indeed. Also, to recognize correctly the
>>> number of solutions with the help of `len` procedure. If we return the
>>> dictionary it is not clear:
>>>
>>>>>> len({x: 3, y: 2})
>>> 2
>>>>>> [{x: 3, y: 2}, {x: 8, y: -3}]
>>> 2 (too)
>>>
>>
>> Until a Solution class exists, the multi-solution case should come back like
>> the single solution: as a list.
>> So solutions will look like `[1]`, ` [1, 2]`, `[{x: 3, y: 2}]` or `[{x: 3,
>> y: 2}, {x: 8, y: -3}]`.
>>
>
> May be....
> As temporary solution.
>
> But if a Solution class will exists, it is not necessary to result a
> list if one solution only. I have pointed out an advantage of this case
> (strict typified interface of function definition) and disadvantage (not
> convenient for end-user).
>
> But I can't decide it, because I do not know exactly the politic way in
> SumPy for this cases (how to manage with variant results).
>
> My opinion that it would be rather suitable:
> `1`, ` [1, 2]`, `{x: 3, y: 2}` or `[{x: 3, y: 2}, {x: 8, y: -3}]`
>
> If Solution class exist, then I check type (list of Solutions or
> Solution itself) with easy.
>
> Also, taking into account Mateusz's notes (e.g. about sorting of
> dictinary) I think that the issue for Solution class should be created
> in issue-tracker too.
>
> --
> Alexey U.
>
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