2015-03-18 12:40 GMT+01:00 Mike Zabrocki <mike.zabro...@gmail.com>:

> That would make sense.  My preference is that (at least for values less
> than 15) the default is that the output is sorted and this can be
> controlled by the optional parameter.
>
> I think about how many times that I test symmetric function identities on
> partitions and realize that patterns that indicate a relation to dominance
> order will be a lot less clear if the order is not something natural.  I
> wouldn't want the interface to be too complicated, but the more I think
> about it the more I realize that my personal use of partitions is very
> dependent on this order.
>

I would tend to agree with you. The order wasn't documented but I'm pretty
sure many people writing some personal code using partitions still rely on
the order somehow. I feel a good choice would be to give the "nice" order
by default and some parameter to obtain the optimized one.



>
> On Wednesday, 18 March 2015 04:20:15 UTC-4, Samuel Lelievre wrote:
>>
>> Nathann Cohen wrote:
>>>
>>> Hello,
>>>
>>> > I think that Partitions should be output in either lex (or possibly
>>> reverse
>>> > lex) since this order is compatible with dominance order.
>>>
>>> I only want to bring to your attention that deciding in which order
>>> the partitions should be returned is not free in terms of
>>> computational time.
>>>
>>> The current implementation returns them in lex order, but returns
>>> *many* wrong answers too (see #17548).
>>>
>>> In order to fix that, Jeroen is re-implementing this feature through a
>>> routine that enumerates the integer points of a polytope (see #17920),
>>> probably without any control over the order in which they are
>>> returned.
>>>
>>> Thus, in order for Partition/Composition to return them in a specific
>>> order we must list them *all* before returning the first of them. This
>>> can really mean hours (or no results at all) instead of seconds on big
>>> instances.
>>>
>>
>> So would it make sense to have an optional parameter sorted=None,
>> which one could set to 'lex' or 'revlex' to get them in a desired order.
>> The documentation could warn about the issues you just raised.
>>
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