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Macaulay2 / M2

The primary source code repository for Macaulay2, a system for computing in commutative algebra, algebraic geometry and related fields.
https://macaulay2.com
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gb computation over ZZ hangs? #292

Open jakobkroeker opened 9 years ago

jakobkroeker commented 9 years ago 
R = ZZ[x_1..x_3, MonomialOrder=>{RevLex}, Global =>false ]

I = ideal(-2+9*x_1^3,-1+3*x_1^2)

gI = ideal gens gb I; -- takes a lot of time, probably does not finish
DanGrayson commented 9 years ago

Since the monomials are not well ordered by this ordering, why should it finish?

On Thu, Jun 4, 2015 at 9:43 PM jakobkroeker notifications@github.com wrote:

R = ZZ[x_1..x_3, MonomialOrder=>{RevLex}, Global =>false ]

I = ideal(-2+9_x_1^3,-1+3_x_1^2)

gI = ideal gens gb I; -- takes a lot of time, probably does not finish

— Reply to this email directly or view it on GitHub https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_Macaulay2_M2_issues_292&d=AwMCaQ&c=8hUWFZcy2Z-Za5rBPlktOQ&r=PAZ_jTPLrSb1btCfAu4RkycWe57N0sGyzbjgeOn2wN0&m=XzTu3TiZJ7c5eZ_1DVJmg4aprZLEcw7iZ9sj3GLA5WA&s=FWpuMxE0lZy0pYoWLa36ckZU2i7pGikaHB_t6Rzz6OQ&e= .

mikestillman commented 9 years ago

This completes the GB internally, and then hangs during minimalization. I'll look into it.

mikestillman commented 9 years ago

It turns out that local ring computations over ZZ are not implemented: the minimalization routine called does not work in this case. Eventually, we should add this. Should we give an error now (local term orders in polynomial rings over ZZ not yet supported?), or is it important enough to do right now?

jakobkroeker commented 9 years ago

It turns out that local ring computations over ZZ are not implemented: the minimalization routine called does not work in this case. Eventually, we should add this. Should we give an error now (local term orders in polynomial rings over ZZ not yet supported?), or is it important enough to do right now?

ask users in Macaulay2 forum?

I'm fine with an error for now (release 1.8)

DanGrayson commented 9 years ago

Presumably, if any wanted it before now, they would have told us before now.

On Fri, Jun 5, 2015 at 12:00 PM jakobkroeker notifications@github.com wrote:

It turns out that local ring computations over ZZ are not implemented: the minimalization routine called does not work in this case. Eventually, we should add this. Should we give an error now (local term orders in polynomial rings over ZZ not yet supported?), or is it important enough to do right now?

ask users in Macaulay2 forum?

I'm fine with an error for now (release 1.8)

— Reply to this email directly or view it on GitHub https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_Macaulay2_M2_issues_292-23issuecomment-2D109341208&d=AwMCaQ&c=8hUWFZcy2Z-Za5rBPlktOQ&r=PAZ_jTPLrSb1btCfAu4RkycWe57N0sGyzbjgeOn2wN0&m=zFwdZhhVW_PP17Wx9us2xB4R0a2qDqIfYtQ78BEvvIo&s=QG5xMKg-bN_3RyJKhHfeRjpo79iWCIz1o_OOYMMLmqc&e= .