.7%
Is that a problem for anyone? I would be surprised if it was.
Rich
--------------------------------------------------
From: "Dieter Kaiser" <drdieterkaiser at web.de>
Sent: Sunday, December 06, 2009 5:02 PM
To: "Richard Fateman" <fateman at cs.berkeley.edu>
Cc: <maxima at math.utexas.edu>; "Barton Willis" <willisb at unk.edu>
Subject: Re: [Maxima] Simplification of infinities
> Am Sonntag, den 06.12.2009, 12:48 -0800 schrieb Richard Fateman:
>> Dieter Kaiser wrote
>>
>> ...
>>
>> > I have done it this way, to avoid to look every time into
>> > the nested lists of an expression.
>> >
>> >
>> That is a big help.
>>
>> Here are some more possible approaches:
>>
>> simplus and simptimes can be given expressions which have, at the
>> top-level, many expressions. (Consider a dense polynomial of degree
>> 10,000).
>>
>> If the subexpressions are sorted, and in the sorting order all the
>> special cases of inf, infinity, und, etc. come out at the front, then
>> it may be
>> faster to find them.
>>
>> Also, intersection may not the be right program, since all you need to
>> know is "is the intersection empty". Intersection keeps on looking,
>> even after
>> the intersection is known to be non-nil. That is, it will look all the
>> way to the end.
>
> Yes, the function intersection might be not the right way to implement
> the algorithm. As written at this time I am interested in a working
> algorithm.
>
> I have tried several attempts to overcome the problems, because of the
> missing handling of infinities. This way is the first which works well
> with the whole core code of Maxima. A lot of problems might vanish or
> work more correct.
>
> I have done a first test to check the time needed for the extra
> overhead. I develop Maxima on a (slow) notebook with CLISP 2.44, Ubuntu
> 9.10, 1800 MHZ, and 355 MB Ram. The realtime and runtime are increased
> about 0,7% with the code to simplify the infinities when I run the
> testsuite.
>
> Dieter Kaiser
>
>
>
>
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