Opened 12 years ago

Closed 12 years ago

#371 closed bug (fixed)

nrroots from rootsur.lib gives wrong results

Reported by: steenpass Owned by: somebody
Priority: minor Milestone: 3-1-4 and higher
Component: singular-libs Version: 3-1-3
Keywords: rootsur.lib Cc:


According to the online manual, nrroots from rootsur.lib gives "the number of real roots" of a polynomial, but it gives strange results in some cases:

> option(noloadLib);
> LIB "rootsur.lib";
> ring r = 0,x,ds;
> nrroots((x-1)*x*(x+1));

One could argue that this result is correct in some sense because ds is a local monomial order and locally at 0, there is only one root. But then what about the following cases?

> nrroots((x-1)*(x+1));
> nrroots((x-1)*(x+1)*(x+2));

Change History (1)

comment:1 Changed 12 years ago by hannes

Resolution: fixed
Status: newclosed

a global ordering is required for proc sturmha (etc.) fixed with rev. 14388

Last edited 12 years ago by hannes (previous) (diff)
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