Opened 8 years ago

Closed 8 years ago

# [with patch] problem in interaction with Singular subprocesses

Reported by: Owned by: cwitty malb major sage-2.8.13 commutative algebra

### Description

The following happens in 2.8.9.rc1, on 32-bit and 64-bit x86 Linux.
Note that the problem does not occur if the "T = ..." line is omitted.

```cwitty@comet:~/sage-2.8.9.rc1\$ ./sage

sage: K.<w> = GF(27)
sage: P.<x, y> = PolynomialRing(K, 2, order='lex')
sage: I = Ideal([ x^8 + y + 2, y^6 + x*y^5 + x^2 ])
sage: T = I.triangular_decomposition('singular:triangLfak')
sage: I.variety()
---------------------------------------------------------------------------
<type 'exceptions.RuntimeError'>          Traceback (most recent call last)

/home/cwitty/sage-2.8.9.rc1/<ipython console> in <module>()

/home/cwitty/sage-2.8.9.rc1/local/lib/python2.5/site-packages/sage/rings/polynomial/multi_polynomial_ideal.py in variety(self)
1113
1114         P = self.ring()
-> 1115         T = self.triangular_decomposition('singular:triangLfak')
1116
1117         V = []

/home/cwitty/sage-2.8.9.rc1/local/lib/python2.5/site-packages/sage/rings/polynomial/multi_polynomial_ideal.py in triangular_decomposition(self, algorithm)
426         P = self.ring()
427
--> 428         is_groebner = self.basis_is_groebner()
429
430         # make sure to work w.r.t. 'lex'

/home/cwitty/sage-2.8.9.rc1/local/lib/python2.5/site-packages/sage/rings/polynomial/multi_polynomial_ideal.py in basis_is_groebner(self)
913         LTF = singular( [f.lt() for f in self.gens()] , "module" )
914
--> 915         M = (F * LTF.syz()).reduce(self._singular_())
916
917         for i in range(M.nrows()):

/home/cwitty/sage-2.8.9.rc1/local/lib/python2.5/site-packages/sage/rings/polynomial/multi_polynomial_ideal.py in _singular_(self, singular)
214         if singular is None: singular = singular_default
215         try:
--> 216             self.ring()._singular_(singular).set_ring()
217             I = self.__singular
218             if not (I.parent() is singular):

/home/cwitty/sage-2.8.9.rc1/multi_polynomial_libsingular.pyx in multi_polynomial_libsingular.MPolynomialRing_libsingular._singular_()

/home/cwitty/sage-2.8.9.rc1/local/lib/python2.5/site-packages/sage/interfaces/singular.py in eval(self, x, allow_semicolon, strip)
372
373             if s.find("error") != -1 or s.find("Segment fault") != -1:
--> 374                 raise RuntimeError, 'Singular error:\n%s'%s
375         finally:
376             gc.enable()

<type 'exceptions.RuntimeError'>: Singular error:
? type 444 too complex...set minpoly before
? error occurred in STDIN line 166: `minpoly=(w^3+2*w+1);`
sage:
```

### comment:1 Changed 8 years ago by malb

• Component changed from algebraic geometry to commutative algebra
• Milestone changed from sage-2.9 to sage-2.8.13
• Owner changed from was to malb
• Status changed from new to assigned
• Summary changed from problem in interaction with Singular subprocesses to [with patch] problem in interaction with Singular subprocesses

The attached patch fixes this issue for me.

### comment:2 Changed 8 years ago by was

Looks good to me, probably. It's just a format issue anyways.

### comment:3 Changed 8 years ago by mabshoff

• Resolution set to fixed
• Status changed from assigned to closed

Merged in 2.8.13.rc1.

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