On Fri, 17 Aug 2007, Joseph L Wetherell wrote:
>
> Robert Bradshaw wrote:
>>
>> On Jul 30, 2007, at 12:26 PM, didier deshommes wrote:
>>
>>> 2007/7/30, Carl Witty <[EMAIL PROTECTED]>:
>>>> It seems pretty strange to me, mostly because you lose too much
>>>> information by eliding zeroes. As far as I can tell, given
>>>> MPolynomialRing(QQ,2,order='lex'), all of the following polynomials:
>>>>
>>>> 3*x^2 + 1
>>>> 3*x^5 + x
>>>> 3*y^7 + 1
>>>> 3*y + 1
>>>>
>>>> would have a coefficients() list of [3, 1]. Is that true, and if so,
>>>> is this really a useful function?
>
> I would think that [3, 1] is the only useful output in all 3 cases.
> After all, there are infinitely many zeros between the 3 and the 1
> in some cases: for example, all the powers of x come between 3*y
> and 1. So what representation that includes zeros would you use?
>
> To keep track of things, you probably want both a function
> coefficients() that returns [3, 1] and a function monomials()
> that returns [y, 1].
+1
Right now, mulivariate polynomial evaluation is dog slow, and I'd like to
attack this using addition chains like I did for univariate. My only attempt
so far failed to give significant improvement because I did so much dictionary
mangling.
--~--~---------~--~----~------------~-------~--~----~
To post to this group, send email to sage-devel@googlegroups.com
To unsubscribe from this group, send email to [EMAIL PROTECTED]
For more options, visit this group at http://groups.google.com/group/sage-devel
URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/
-~----------~----~----~----~------~----~------~--~---
