LinearCode.minimum_distance "Gap terminated unexpectedly while reading in a large line" #25719
Description
When computing the minimum distance of a linear code defined by a matrix over an quotient ring, gap crashes with the following error:
% sage
┌────────────────────────────────────────────────────────────────────┐
│ SageMath version 8.3.beta7, Release Date: 2018-06-23 │
│ Type "notebook()" for the browser-based notebook interface. │
│ Type "help()" for help. │
└────────────────────────────────────────────────────────────────────┘
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┃ Warning: this is a prerelease version, and it may be unstable. ┃
┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛
sage: from sage.coding.linear_code import LinearCode
....: R = GF(2)['x'].quo(GF(2)['x']("x^4+x+1"))
....: LinearCode(matrix(R, 2, 2, map(R, ["1","1","1","1"]))).minimum_distance()
....:
---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
<ipython-input-1-4142638f6b1f> in <module>()
1 from sage.coding.linear_code import LinearCode
2 R = GF(Integer(2))['x'].quo(GF(Integer(2))['x']("x^4+x+1"))
----> 3 LinearCode(matrix(R, Integer(2), Integer(2), map(R, ["1","1","1","1"]))).minimum_distance()
/home/asante/.local/src/sage/local/lib/python2.7/site-packages/sage/misc/cachefunc.pyx in sage.misc.cachefunc.CachedMethodCaller.__call__ (build/cythonized/sage/misc/cachefunc.c:10823)()
1951 return cache[k]
1952 except KeyError:
-> 1953 w = self._instance_call(*args, **kwds)
1954 cache[k] = w
1955 return w
/home/asante/.local/src/sage/local/lib/python2.7/site-packages/sage/misc/cachefunc.pyx in sage.misc.cachefunc.CachedMethodCaller._instance_call (build/cythonized/sage/misc/cachefunc.c:10279)()
1827 True
1828 """
-> 1829 return self.f(self._instance, *args, **kwds)
1830
1831 cdef fix_args_kwds(self, tuple args, dict kwds):
/home/asante/.local/src/sage/local/lib/python2.7/site-packages/sage/coding/linear_code.pyc in minimum_distance(self, algorithm)
2574 d = C.MinimumWeight()
2575 return ZZ(d)
-> 2576 return self._minimum_weight_codeword(algorithm).hamming_weight()
2577
2578 def _minimum_weight_codeword(self, algorithm = None):
/home/asante/.local/src/sage/local/lib/python2.7/site-packages/sage/coding/linear_code.pyc in _minimum_weight_codeword(self, algorithm)
2617 n, k = self.length(), self.dimension()
2618 F = self.base_field()
-> 2619 Gmat = self.generator_matrix()._gap_init_()
2620
2621 current_randstate().set_seed_gap()
/home/asante/.local/src/sage/local/lib/python2.7/site-packages/sage/matrix/matrix1.pyx in sage.matrix.matrix1.Matrix._gap_init_ (build/cythonized/sage/matrix/matrix1.c:3341)()
139 # It is needed to multiply with 'One(...)', because
140 # otherwise the result would not be a gap matrix
--> 141 return '[%s]*One(%s)'%(','.join(v),sage.interfaces.gap.gap(self.base_ring()).name())
142
143 def _libgap_(self):
/home/asante/.local/src/sage/local/lib/python2.7/site-packages/sage/interfaces/interface.pyc in __call__(self, x, name)
280 return cls(self, x, name=name)
281 try:
--> 282 return self._coerce_from_special_method(x)
283 except TypeError:
284 raise
/home/asante/.local/src/sage/local/lib/python2.7/site-packages/sage/interfaces/interface.pyc in _coerce_from_special_method(self, x)
306 s = '_gp_'
307 try:
--> 308 return (x.__getattribute__(s))(self)
309 except AttributeError:
310 return self(x._interface_init_())
/home/asante/.local/src/sage/local/lib/python2.7/site-packages/sage/structure/sage_object.pyx in sage.structure.sage_object.SageObject._gap_ (build/cythonized/sage/structure/sage_object.c:6377)()
752 import sage.interfaces.gap
753 G = sage.interfaces.gap.gap
--> 754 return self._interface_(G)
755
756 def _gap_init_(self):
/home/asante/.local/src/sage/local/lib/python2.7/site-packages/sage/structure/sage_object.pyx in sage.structure.sage_object.SageObject._interface_ (build/cythonized/sage/structure/sage_object.c:5894)()
728 except Exception:
729 raise NotImplementedError("coercion of object %s to %s not implemented:\n%s\n%s" % (repr(self), I))
--> 730 X = I(s)
731 if c:
732 try:
/home/asante/.local/src/sage/local/lib/python2.7/site-packages/sage/interfaces/interface.pyc in __call__(self, x, name)
278
279 if isinstance(x, string_types):
--> 280 return cls(self, x, name=name)
281 try:
282 return self._coerce_from_special_method(x)
/home/asante/.local/src/sage/local/lib/python2.7/site-packages/sage/interfaces/expect.pyc in __init__(self, parent, value, is_name, name)
1443 except (RuntimeError, ValueError) as x:
1444 self._session_number = -1
-> 1445 raise_(TypeError, TypeError(*x.args), sys.exc_info()[2])
1446 except BaseException:
1447 self._session_number = -1
/home/asante/.local/src/sage/local/lib/python2.7/site-packages/sage/interfaces/expect.pyc in __init__(self, parent, value, is_name, name)
1438 else:
1439 try:
-> 1440 self._name = parent._create(value, name=name)
1441 # Convert ValueError and RuntimeError to TypeError for
1442 # coercion to work properly.
/home/asante/.local/src/sage/local/lib/python2.7/site-packages/sage/interfaces/interface.pyc in _create(self, value, name)
474 def _create(self, value, name=None):
475 name = self._next_var_name() if name is None else name
--> 476 self.set(name, value)
477 return name
478
/home/asante/.local/src/sage/local/lib/python2.7/site-packages/sage/interfaces/gap.pyc in set(self, var, value)
1387 """
1388 cmd = ('%s:=%s;;' % (var, value)).replace('\n','')
-> 1389 self._eval_line(cmd, allow_use_file=True)
1390
1391 def get(self, var, use_file=False):
/home/asante/.local/src/sage/local/lib/python2.7/site-packages/sage/interfaces/gap.pyc in _eval_line(self, line, allow_use_file, wait_for_prompt, restart_if_needed)
787 return ''
788 else:
--> 789 raise RuntimeError(message)
790
791 except KeyboardInterrupt:
TypeError: Gap terminated unexpectedly while reading in a large line:
Gap produced error output
Error, Variable: 'Univariate' must have a value
Syntax error: ; expected in /home/asante/.sage/temp/Thalamus/21109/interface/t\
mp21147 line 1
\$sage1:=Univariate Quotient Polynomial Ring in xbar over Finite Field of size\
2 with modulus x^4 + x + 1;;
^
executing Read("/home/asante/.sage/temp/Thalamus/21109/interface/tmp21147");(this is a 64bit linux machine, if this is necessary..)
Component: coding theory
Keywords: days94
Issue created by migration from https://trac.sagemath.org/ticket/25719