On Oct 31, 11:27 pm, Michael Brickenstein <[EMAIL PROTECTED]> wrote:
> Even, if that bug wouldn't exist, I can only recommend
> to do such computation over the rationals, if possible.
>
> Gröbner bases and similar computations (like syzygies) over floating
> point numbers are
> very problematic: What is the leading term of a polynomial, where you
> can't exactly determine, which coefficient is
> zero.
Agreed, this is certainly a mine field :)
> Michael
>
> On 31 Okt., 15:05, Martin Albrecht <[EMAIL PROTECTED]>
> wrote:
>
> > On Monday 27 October 2008, mmarco wrote:
>
> > > R.<x,y,z>=PolynomialRing(CC)
> > > config2=(x^2+8*y^2+21*x*y-x*z-8*y*z)*(x^2+5*y^2+13*x*y-
> > > x*z-5*y*z)*(x^2+9*y^2-4*x*y-x*z-9*y*z)*(x^2+11*y^2+x*y-
> > > x*z-11*y*z)*(x^2+17*y^2-5*x*y-x*z-17*y*z)
> > > miid=R.ideal(diff(config2,x),diff(config2,y),diff(config2,z),config2)
>
> > Hi,
>
> > it seems Singular chokes on the scientific notation:
>
> > sage: R.<x,y,z>=PolynomialRing(CC)
> > sage: f = 1.0*10^7 *x; f
> > 1.00000000000000e7*x
> > sage: f._singular_()
> > TypeError: Singular error:
> > ? error occurred in STDIN line 55: `def sage11=1.00000000000000e7*x;`
> > ? last reserved name was `def`
>
> > It seems real numbers support a no_sci printing parameter but complex
> > numbers
> > don't.
Shouldn't we open a ticket for this?
> > Cheers,
> > Martin
Cheers,
Michael
> > --
> > name: Martin Albrecht
> > _pgp:http://pgp.mit.edu:11371/pks/lookup?op=get&search=0x8EF0DC99
> > _www:http://www.informatik.uni-bremen.de/~malb
> > _jab: [EMAIL PROTECTED]
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