Opened 5 years ago

Closed 5 years ago

#815 closed bug (postponed)

Singular and Sagemath

Reported by: artal@… Owned by: somebody
Priority: minor Milestone: 4-2-0 and higher
Component: dontKnow Version: 4-1-0
Keywords: Cc:


I think this bug is more a sage bug than a singular bug but since its solution may depend on how singular works I put it here. In sage (version 8.1, but 8.0 has the same issue) I have the following code:

R.<x,y>=PolynomialRing?(QQ,order='neglex') f=(y2+x3)*(y2+x3+x2*y) singular.lib("all.lib") f._singular_().bernstein()

I guess this is equivalent to the following singular code

LIB "all.lib"; ring r=0,(x,y),ds; poly f=(y2+x3)*(y2+x3+x2y) bernstein(f)

The results differ: -11/7 is a root in the first case, while -4/7 in the second (and I think there are theoretical results that ensure the second one is correct); moreover in both cases, when using bfct -4/7 is the root.

In other cases I had communication problems between singular and sage but I cannot understand what produces (a non evident) mathematical wrong result.

Anyway, thanks for the great work in Singular.

Change History (1)

comment:1 Changed 5 years ago by hannes

Resolution: postponed
Status: newclosed

order='neglex' is in Singular called ls. Many commands require for local orderings a degree ordering, i.e. use order='negdegrevlex' in Sage. We will try to add additional checks for valid orderings.

Note: See TracTickets for help on using tickets.