Sorry, maybe I used the wrong command.
What I wanted to do is work over polynomials over Z_2
and not integers over Z_2.
Maybe I did something wrong
I did not want to convert
Z->Z_2
Instead I thought I was doing
Z[x]->Z_2[x]
and
gcd is meaningful in Z_2[x]
I thought that setting modulus:2 meant that
only the polynomial computation would be over polynomial
over Z_2 (the coefficients would be converted and not the
whole polynomial)
Is there a correct way to tell Maxima to work in Z_p[x]?
Fabrizio
On Mon, 12 Dec 2005, Richard Fateman wrote:
> I think it requires a little bit of math to decide what is going on here.
> The notion of greatest common divisor combines TWO notions.
> Common divisor
>
> and
> Greatest.
>
> Since the numbers in a finite field, e.g. with modulus =some prime,
> all have inverses, except for 0, they are all divisors of each
> other (except 0).
>
> Of all the divisors, which should you choose? Since the notion
> of order, and hence greatest, is not usually defined for finite
> fields, neither is GCD.
>
> So it is not entirely the fault of the gcd program. Perhaps your
> question doesn't make sense.
>
> Should there be an error message?
> RJF
>
>
> Robert Dodier wrote:
>
> >hi fabrizio,
> >
> >
> >
> >>As a reminder I also re-report the
> >>problem with "mod".
> >>
> >>mod is still not defined for "1".
> >>
> >>
> >
> >i think we need a little more context here. mod has recently
> >(post 5.9.2) been changed; mod was renamed to polymod
> >and nummod was renamed to mod. what version are you
> >running? also, the global variable modulus is nil by default,
> >which probably explains the error message ("NIL is not of
> >type NUMBER") i see when i launch maxima (5.9.1 or 5.9.2)
> >and enter mod(1). however after assigning modulus a value,
> >mod(1) is OK. so maybe you can be a little more explicit
> >about the sequence of operations here. is it only mod(1)
> >which is problematic? is mod(2) OK or not?
> >
> >it would also probably help to report bugs to the sourceforge
> >bug tracker in addition to posting them to the mailing list.
> >
> >all the best,
> >robert dodier
> >
> >_______________________________________________
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> >Maxima@math.utexas.edu
> >http://www.math.utexas.edu/mailman/listinfo/maxima
> >
> >
>