예제 #1
0
파일: qmodnz.py 프로젝트: swewers/mein_sage
    def _coerce_map_from_(self, S):
        r"""
        Coercion from a parent ``S``.

        There is a coercion from ``S`` if ``S`` has a coerce map to `\Q`
        or if `S = \Q/m\Z` for `m` a multiple of `n`.

        TESTS::

            sage: G2 = QQ/(2*ZZ)
            sage: G3 = QQ/(3*ZZ)
            sage: G4 = QQ/(4*ZZ)
            sage: G2.has_coerce_map_from(QQ)
            True
            sage: G2.has_coerce_map_from(ZZ)
            True
            sage: G2.has_coerce_map_from(ZZ['x'])
            False
            sage: G2.has_coerce_map_from(G3)
            False
            sage: G2.has_coerce_map_from(G4)
            True
            sage: G4.has_coerce_map_from(G2)
            False
        """
        if QQ.has_coerce_map_from(S):
            return True
        if isinstance(S, QmodnZ) and (S.n / self.n in ZZ):
            return True
예제 #2
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    def __add__(self, other):
        r"""
        Return the subgroup of `\QQ` generated by this group and ``other``.

        INPUT:

        - ``other`` -- a discrete value group or a rational number

        EXAMPLES::

            sage: D = DiscreteValueGroup(1/2)
            sage: D + 1/3
            DiscreteValueGroup(1/6)
            sage: D + D
            DiscreteValueGroup(1/2)
            sage: D + 1
            DiscreteValueGroup(1/2)
            sage: DiscreteValueGroup(2/7) + DiscreteValueGroup(4/9)
            DiscreteValueGroup(2/63)

        """
        if not isinstance(other, DiscreteValueGroup):
            from sage.structure.element import is_Element
            if is_Element(other) and QQ.has_coerce_map_from(other.parent()):
                return self + DiscreteValueGroup(other, category=self.category())
            raise ValueError("`other` must be a DiscreteValueGroup or a rational number")
        if self.category() is not other.category():
            raise ValueError("`other` must be in the same category")
        return DiscreteValueGroup(self._generator.gcd(other._generator), category=self.category())
예제 #3
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    def __add__(self, other):
        r"""
        Return the subgroup of \QQ generated by this group and ``other``.

        INPUT:

        - ``other`` -- a discrete value group or a rational number

        EXAMPLES::

            sage: D = DiscreteValueGroup(1/2)
            sage: D + 1/3
            DiscreteValueGroup(1/6)
            sage: D + D
            DiscreteValueGroup(1/2)
            sage: D + 1
            DiscreteValueGroup(1/2)
            sage: DiscreteValueGroup(2/7) + DiscreteValueGroup(4/9)
            DiscreteValueGroup(2/63)

        """
        if not isinstance(other, DiscreteValueGroup):
            from sage.structure.element import is_Element
            if is_Element(other) and QQ.has_coerce_map_from(other.parent()):
                return self + DiscreteValueGroup(other,
                                                 category=self.category())
            raise ValueError(
                "`other` must be a DiscreteValueGroup or a rational number")
        if self.category() is not other.category():
            raise ValueError("`other` must be in the same category")
        return DiscreteValueGroup(self._generator.gcd(other._generator),
                                  category=self.category())
예제 #4
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    def __add__(self, other):
        r"""
        Return the subsemigroup of `\QQ` generated by this semigroup and ``other``.

        INPUT:

        - ``other`` -- a discrete value (semi-)group or a rational number

        EXAMPLES::

            sage: from sage.rings.valuation.value_group import DiscreteValueSemigroup, DiscreteValueGroup
            sage: D = DiscreteValueSemigroup(1/2)
            sage: D + 1/3
            Additive Abelian Semigroup generated by 1/3, 1/2
            sage: D + D
            Additive Abelian Semigroup generated by 1/2
            sage: D + 1
            Additive Abelian Semigroup generated by 1/2
            sage: DiscreteValueGroup(2/7) + DiscreteValueSemigroup(4/9)
            Additive Abelian Semigroup generated by -2/7, 2/7, 4/9

        """
        if isinstance(other, DiscreteValueSemigroup):
            return DiscreteValueSemigroup(self._generators + other._generators)
        if isinstance(other, DiscreteValueGroup):
            return DiscreteValueSemigroup(self._generators + (other._generator, -other._generator))
        from sage.structure.element import is_Element
        if is_Element(other) and QQ.has_coerce_map_from(other.parent()):
            return self + DiscreteValueSemigroup(other)
        raise ValueError("`other` must be a DiscreteValueGroup, a DiscreteValueSemigroup or a rational number")
예제 #5
0
    def __add__(self, other):
        r"""
        Return the subsemigroup of \QQ generated by this semigroup and ``other``.

        INPUT:

        - ``other`` -- a discrete value (semi-)group or a rational number

        EXAMPLES::

            sage: sys.path.append(os.getcwd()); from mac_lane import * # optional: standalone
            sage: D = DiscreteValueSemigroup(1/2)
            sage: D + 1/3
            Additive Abelian Semigroup generated by 1/3, 1/2
            sage: D + D
            Additive Abelian Semigroup generated by 1/2
            sage: D + 1
            Additive Abelian Semigroup generated by 1/2
            sage: DiscreteValueGroup(2/7) + DiscreteValueSemigroup(4/9)
            Additive Abelian Semigroup generated by -2/7, 2/7, 4/9

        """
        if isinstance(other, DiscreteValueSemigroup):
            return DiscreteValueSemigroup(self._generators + other._generators)
        if isinstance(other, DiscreteValueGroup):
            return DiscreteValueSemigroup(self._generators +
                                          (other._generator,
                                           -other._generator))
        from sage.structure.element import is_Element
        if is_Element(other) and QQ.has_coerce_map_from(other.parent()):
            return self + DiscreteValueSemigroup(other)
        raise ValueError(
            "`other` must be a DiscreteValueGroup, a DiscreteValueSemigroup or a rational number"
        )
예제 #6
0
파일: value_group.py 프로젝트: yabirgb/sage
    def __add__(self, other):
        r"""
        Return the subgroup of `\QQ` generated by this group and ``other``.

        INPUT:

        - ``other`` -- a discrete value group or a rational number

        EXAMPLES::

            sage: from sage.rings.valuation.value_group import DiscreteValueGroup
            sage: D = DiscreteValueGroup(1/2)
            sage: D + 1/3
            Additive Abelian Group generated by 1/6
            sage: D + D
            Additive Abelian Group generated by 1/2
            sage: D + 1
            Additive Abelian Group generated by 1/2
            sage: DiscreteValueGroup(2/7) + DiscreteValueGroup(4/9)
            Additive Abelian Group generated by 2/63

        """
        if isinstance(other, DiscreteValueGroup):
            return DiscreteValueGroup(self._generator.gcd(other._generator))
        if isinstance(other, DiscreteValueSemigroup):
            return other + self
        from sage.structure.element import is_Element
        if is_Element(other) and QQ.has_coerce_map_from(other.parent()):
            return self + DiscreteValueGroup(other)
        raise ValueError("`other` must be a DiscreteValueGroup or a rational number")
예제 #7
0
def Polyhedron(vertices=None,
               rays=None,
               lines=None,
               ieqs=None,
               eqns=None,
               ambient_dim=None,
               base_ring=None,
               minimize=True,
               verbose=False,
               backend=None):
    """
    Construct a polyhedron object.

    You may either define it with vertex/ray/line or
    inequalities/equations data, but not both. Redundant data will
    automatically be removed (unless ``minimize=False``), and the
    complementary representation will be computed.

    INPUT:

    - ``vertices`` -- list of point. Each point can be specified as
      any iterable container of ``base_ring`` elements. If ``rays`` or
      ``lines`` are specified but no ``vertices``, the origin is
      taken to be the single vertex.

    - ``rays`` -- list of rays. Each ray can be specified as any
      iterable container of ``base_ring`` elements.

    - ``lines`` -- list of lines. Each line can be specified as any
      iterable container of ``base_ring`` elements.

    - ``ieqs`` -- list of inequalities. Each line can be specified as any
      iterable container of ``base_ring`` elements. An entry equal to
      ``[-1,7,3,4]`` represents the inequality `7x_1+3x_2+4x_3\geq 1`.

    - ``eqns`` -- list of equalities. Each line can be specified as
      any iterable container of ``base_ring`` elements. An entry equal to
      ``[-1,7,3,4]`` represents the equality `7x_1+3x_2+4x_3= 1`.

    - ``base_ring`` -- a sub-field of the reals implemented in
      Sage. The field over which the polyhedron will be defined. For
      ``QQ`` and algebraic extensions, exact arithmetic will be
      used. For ``RDF``, floating point numbers will be used. Floating
      point arithmetic is faster but might give the wrong result for
      degenerate input.

    - ``ambient_dim`` -- integer. The ambient space dimension. Usually
      can be figured out automatically from the H/Vrepresentation
      dimensions.

    - ``backend`` -- string or ``None`` (default). The backend to use. Valid choices are

      * ``'cdd'``: use cdd
        (:mod:`~sage.geometry.polyhedron.backend_cdd`) with `\QQ` or
        `\RDF` coefficients depending on ``base_ring``.

      * ``'ppl'``: use ppl
        (:mod:`~sage.geometry.polyhedron.backend_ppl`) with `\ZZ` or
        `\QQ` coefficients depending on ``base_ring``.

      * ``'field'``: use python implementation
        (:mod:`~sage.geometry.polyhedron.backend_field`) for any field

    Some backends support further optional arguments:

    - ``minimize`` -- boolean (default: ``True``). Whether to
      immediately remove redundant H/V-representation data. Currently
      not used.

    - ``verbose`` -- boolean (default: ``False``). Whether to print
      verbose output for debugging purposes. Only supported by the cdd
      backends.

    OUTPUT:

    The polyhedron defined by the input data.

    EXAMPLES:

    Construct some polyhedra::

        sage: square_from_vertices = Polyhedron(vertices = [[1, 1], [1, -1], [-1, 1], [-1, -1]])
        sage: square_from_ieqs = Polyhedron(ieqs = [[1, 0, 1], [1, 1, 0], [1, 0, -1], [1, -1, 0]])
        sage: list(square_from_ieqs.vertex_generator())
        [A vertex at (1, -1),
         A vertex at (1, 1),
         A vertex at (-1, 1),
         A vertex at (-1, -1)]
        sage: list(square_from_vertices.inequality_generator())
        [An inequality (1, 0) x + 1 >= 0,
         An inequality (0, 1) x + 1 >= 0,
         An inequality (-1, 0) x + 1 >= 0,
         An inequality (0, -1) x + 1 >= 0]
        sage: p = Polyhedron(vertices = [[1.1, 2.2], [3.3, 4.4]], base_ring=RDF)
        sage: p.n_inequalities()
        2

    The same polyhedron given in two ways::

        sage: p = Polyhedron(ieqs = [[0,1,0,0],[0,0,1,0]])
        sage: p.Vrepresentation()
        (A line in the direction (0, 0, 1),
         A ray in the direction (1, 0, 0),
         A ray in the direction (0, 1, 0),
         A vertex at (0, 0, 0))
        sage: q = Polyhedron(vertices=[[0,0,0]], rays=[[1,0,0],[0,1,0]], lines=[[0,0,1]])
        sage: q.Hrepresentation()
        (An inequality (1, 0, 0) x + 0 >= 0,
         An inequality (0, 1, 0) x + 0 >= 0)

    Finally, a more complicated example. Take `\mathbb{R}_{\geq 0}^6` with
    coordinates `a, b, \dots, f` and

      * The inequality `e+b \geq c+d`
      * The inequality `e+c \geq b+d`
      * The equation `a+b+c+d+e+f = 31`

    ::

        sage: positive_coords = Polyhedron(ieqs=[
        ...       [0, 1, 0, 0, 0, 0, 0], [0, 0, 1, 0, 0, 0, 0], [0, 0, 0, 1, 0, 0, 0],
        ...       [0, 0, 0, 0, 1, 0, 0], [0, 0, 0, 0, 0, 1, 0], [0, 0, 0, 0, 0, 0, 1]])
        sage: P = Polyhedron(ieqs=positive_coords.inequalities() + (
        ...       [0,0,1,-1,-1,1,0], [0,0,-1,1,-1,1,0]), eqns=[[-31,1,1,1,1,1,1]])
        sage: P
        A 5-dimensional polyhedron in QQ^6 defined as the convex hull of 7 vertices
        sage: P.dim()
        5
        sage: P.Vrepresentation()
        (A vertex at (31, 0, 0, 0, 0, 0), A vertex at (0, 0, 0, 0, 0, 31),
         A vertex at (0, 0, 0, 0, 31, 0), A vertex at (0, 0, 31/2, 0, 31/2, 0),
         A vertex at (0, 31/2, 31/2, 0, 0, 0), A vertex at (0, 31/2, 0, 0, 31/2, 0),
         A vertex at (0, 0, 0, 31/2, 31/2, 0))

    .. NOTE::

      * Once constructed, a ``Polyhedron`` object is immutable.

      * Although the option ``field=RDF`` allows numerical data to
        be used, it might not give the right answer for degenerate
        input data - the results can depend upon the tolerance
        setting of cdd.
    """
    # Clean up the arguments
    vertices = _make_listlist(vertices)
    rays = _make_listlist(rays)
    lines = _make_listlist(lines)
    ieqs = _make_listlist(ieqs)
    eqns = _make_listlist(eqns)

    got_Vrep = (len(vertices + rays + lines) > 0)
    got_Hrep = (len(ieqs + eqns) > 0)

    if got_Vrep and got_Hrep:
        raise ValueError('You cannot specify both H- and V-representation.')
    elif got_Vrep:
        deduced_ambient_dim = _common_length_of(vertices, rays, lines)[1]
    elif got_Hrep:
        deduced_ambient_dim = _common_length_of(ieqs, eqns)[1] - 1
    else:
        if ambient_dim is None:
            deduced_ambient_dim = 0
        else:
            deduced_ambient_dim = ambient_dim
        if base_ring is None:
            base_ring = ZZ

    # set ambient_dim
    if ambient_dim is not None and deduced_ambient_dim != ambient_dim:
        raise ValueError(
            'Ambient space dimension mismatch. Try removing the "ambient_dim" parameter.'
        )
    ambient_dim = deduced_ambient_dim

    # figure out base_ring
    from sage.misc.flatten import flatten
    values = flatten(vertices + rays + lines + ieqs + eqns)
    if base_ring is not None:
        try:
            convert = not all(x.parent() is base_ring for x in values)
        except AttributeError:  # No x.parent() method?
            convert = True
    else:
        from sage.rings.integer import is_Integer
        from sage.rings.rational import is_Rational
        from sage.rings.real_double import is_RealDoubleElement
        if all(is_Integer(x) for x in values):
            if got_Vrep:
                base_ring = ZZ
            else:  # integral inequalities usually do not determine a lattice polytope!
                base_ring = QQ
            convert = False
        elif all(is_Rational(x) for x in values):
            base_ring = QQ
            convert = False
        elif all(is_RealDoubleElement(x) for x in values):
            base_ring = RDF
            convert = False
        else:
            try:
                for v in values:
                    ZZ(v)
                if got_Vrep:
                    base_ring = ZZ
                else:
                    base_ring = QQ
                convert = True
            except (TypeError, ValueError):
                from sage.structure.sequence import Sequence
                values = Sequence(values)
                common_ring = values.universe()
                if QQ.has_coerce_map_from(common_ring):
                    base_ring = QQ
                    convert = True
                elif common_ring is RR:  # DWIM: replace with RDF
                    base_ring = RDF
                    convert = True
                else:
                    base_ring = common_ring
                    convert = True

    # Add the origin if necesarry
    if got_Vrep and len(vertices) == 0:
        vertices = [[0] * ambient_dim]

    # Specific backends can override the base_ring
    from sage.geometry.polyhedron.parent import Polyhedra
    parent = Polyhedra(base_ring, ambient_dim, backend=backend)
    base_ring = parent.base_ring()

    # finally, construct the Polyhedron
    Hrep = Vrep = None
    if got_Hrep:
        Hrep = [ieqs, eqns]
    if got_Vrep:
        Vrep = [vertices, rays, lines]
    return parent(Vrep, Hrep, convert=convert, verbose=verbose)
예제 #8
0
파일: cusps.py 프로젝트: yjjcc/sage
 def _coerce_map_from_(self, R):
     if QQ.has_coerce_map_from(R):
         return True
     if R is InfinityRing:
         return True
     return False
예제 #9
0
파일: path.py 프로젝트: videlec/ore_algebra
    def __init__(self, point, dop=None):
        """
        TESTS::

            sage: from ore_algebra import *
            sage: from ore_algebra.analytic.path import Point
            sage: Dops, x, Dx = DifferentialOperators()
            sage: [Point(z, Dx)
            ....:  for z in [1, 1/2, 1+I, QQbar(I), RIF(1/3), CIF(1/3), pi,
            ....:  RDF(1), CDF(I), 0.5r, 0.5jr, 10r, QQbar(1), AA(1/3)]]
            [1, 1/2, I + 1, I, [0.333333333333333...], [0.333333333333333...],
            3.141592653589794?, 1.000000000000000, 1.000000000000000*I,
            0.5000000000000000, 0.5000000000000000*I, 10, 1, 1/3]
            sage: Point(sqrt(2), Dx).iv()
            [1.414...]
        """
        SageObject.__init__(self)

        from sage.rings.complex_double import ComplexDoubleField_class
        from sage.rings.complex_field import ComplexField_class
        from sage.rings.complex_interval_field import ComplexIntervalField_class
        from sage.rings.real_double import RealDoubleField_class
        from sage.rings.real_mpfi import RealIntervalField_class
        from sage.rings.real_mpfr import RealField_class

        point = sage.structure.coerce.py_scalar_to_element(point)
        try:
            parent = point.parent()
        except AttributeError:
            raise TypeError("unexpected value for point: " + repr(point))
        if isinstance(point, Point):
            self.value = point.value
        elif isinstance(
                parent,
            (number_field_base.NumberField, RealBallField, ComplexBallField)):
            self.value = point
        elif QQ.has_coerce_map_from(parent):
            self.value = QQ.coerce(point)
        # must come before QQbar, due to a bogus coerce map (#14485)
        elif parent is sage.symbolic.ring.SR:
            try:
                return self.__init__(point.pyobject(), dop)
            except TypeError:
                pass
            try:
                return self.__init__(QQbar(point), dop)
            except (TypeError, ValueError, NotImplementedError):
                pass
            try:
                self.value = RLF(point)
            except (TypeError, ValueError):
                self.value = CLF(point)
        elif QQbar.has_coerce_map_from(parent):
            alg = QQbar.coerce(point)
            NF, val, hom = alg.as_number_field_element()
            if NF is QQ:
                self.value = QQ.coerce(val)  # parent may be ZZ
            else:
                embNF = number_field.NumberField(NF.polynomial(),
                                                 NF.variable_name(),
                                                 embedding=hom(NF.gen()))
                self.value = val.polynomial()(embNF.gen())
        elif isinstance(
                parent,
            (RealField_class, RealDoubleField_class, RealIntervalField_class)):
            self.value = RealBallField(point.prec())(point)
        elif isinstance(parent, (ComplexField_class, ComplexDoubleField_class,
                                 ComplexIntervalField_class)):
            self.value = ComplexBallField(point.prec())(point)
        else:
            try:
                self.value = RLF.coerce(point)
            except TypeError:
                self.value = CLF.coerce(point)
        parent = self.value.parent()
        assert (isinstance(
            parent,
            (number_field_base.NumberField, RealBallField, ComplexBallField))
                or parent is RLF or parent is CLF)

        self.dop = dop or point.dop

        self.keep_value = False
예제 #10
0
def Polyhedron(vertices=None, rays=None, lines=None,
               ieqs=None, eqns=None,
               ambient_dim=None, base_ring=None, minimize=True, verbose=False,
               backend=None):
    """
    Construct a polyhedron object.

    You may either define it with vertex/ray/line or
    inequalities/equations data, but not both. Redundant data will
    automatically be removed (unless ``minimize=False``), and the
    complementary representation will be computed.

    INPUT:

    - ``vertices`` -- list of point. Each point can be specified as
      any iterable container of ``base_ring`` elements. If ``rays`` or
      ``lines`` are specified but no ``vertices``, the origin is
      taken to be the single vertex.

    - ``rays`` -- list of rays. Each ray can be specified as any
      iterable container of ``base_ring`` elements.

    - ``lines`` -- list of lines. Each line can be specified as any
      iterable container of ``base_ring`` elements.

    - ``ieqs`` -- list of inequalities. Each line can be specified as any
      iterable container of ``base_ring`` elements. An entry equal to
      ``[-1,7,3,4]`` represents the inequality `7x_1+3x_2+4x_3\geq 1`.

    - ``eqns`` -- list of equalities. Each line can be specified as
      any iterable container of ``base_ring`` elements. An entry equal to
      ``[-1,7,3,4]`` represents the equality `7x_1+3x_2+4x_3= 1`.

    - ``base_ring`` -- either ``QQ`` or ``RDF``. The field over which
      the polyhedron will be defined. For ``QQ``, exact arithmetic
      will be used. For ``RDF``, floating point numbers will be
      used. Floating point arithmetic is faster but might give the
      wrong result for degenerate input.

    - ``ambient_dim`` -- integer. The ambient space dimension. Usually
      can be figured out automatically from the H/Vrepresentation
      dimensions.

    - ``backend`` -- string or ``None`` (default). The backend to use. Valid choices are

      * ``'cdd'``: use cdd
        (:mod:`~sage.geometry.polyhedron.backend_cdd`) with `\QQ` or
        `\RDF` coefficients depending on ``base_ring``.


      * ``'ppl'``: use ppl
        (:mod:`~sage.geometry.polyhedron.backend_ppl`) with `\ZZ` or
        `\QQ` coefficients depending on ``base_ring``.

    Some backends support further optional arguments:

    - ``minimize`` -- boolean (default: ``True``). Whether to
      immediately remove redundant H/V-representation data. Currently
      not used.

    - ``verbose`` -- boolean (default: ``False``). Whether to print
      verbose output for debugging purposes. Only supported by the cdd
      backends.

    OUTPUT:

    The polyhedron defined by the input data.

    EXAMPLES:

    Construct some polyhedra::

        sage: square_from_vertices = Polyhedron(vertices = [[1, 1], [1, -1], [-1, 1], [-1, -1]])
        sage: square_from_ieqs = Polyhedron(ieqs = [[1, 0, 1], [1, 1, 0], [1, 0, -1], [1, -1, 0]])
        sage: list(square_from_ieqs.vertex_generator())
        [A vertex at (1, -1),
         A vertex at (1, 1),
         A vertex at (-1, 1),
         A vertex at (-1, -1)]
        sage: list(square_from_vertices.inequality_generator())
        [An inequality (1, 0) x + 1 >= 0,
         An inequality (0, 1) x + 1 >= 0,
         An inequality (-1, 0) x + 1 >= 0,
         An inequality (0, -1) x + 1 >= 0]
        sage: p = Polyhedron(vertices = [[1.1, 2.2], [3.3, 4.4]], base_ring=RDF)
        sage: p.n_inequalities()
        2

    The same polyhedron given in two ways::

        sage: p = Polyhedron(ieqs = [[0,1,0,0],[0,0,1,0]])
        sage: p.Vrepresentation()
        (A line in the direction (0, 0, 1),
         A ray in the direction (1, 0, 0),
         A ray in the direction (0, 1, 0),
         A vertex at (0, 0, 0))
        sage: q = Polyhedron(vertices=[[0,0,0]], rays=[[1,0,0],[0,1,0]], lines=[[0,0,1]])
        sage: q.Hrepresentation()
        (An inequality (1, 0, 0) x + 0 >= 0,
         An inequality (0, 1, 0) x + 0 >= 0)

    Finally, a more complicated example. Take `\mathbb{R}_{\geq 0}^6` with
    coordinates `a, b, \dots, f` and

      * The inequality `e+b \geq c+d`
      * The inequality `e+c \geq b+d`
      * The equation `a+b+c+d+e+f = 31`

    ::

        sage: positive_coords = Polyhedron(ieqs=[
        ...       [0, 1, 0, 0, 0, 0, 0], [0, 0, 1, 0, 0, 0, 0], [0, 0, 0, 1, 0, 0, 0],
        ...       [0, 0, 0, 0, 1, 0, 0], [0, 0, 0, 0, 0, 1, 0], [0, 0, 0, 0, 0, 0, 1]])
        sage: P = Polyhedron(ieqs=positive_coords.inequalities() + (
        ...       [0,0,1,-1,-1,1,0], [0,0,-1,1,-1,1,0]), eqns=[[-31,1,1,1,1,1,1]])
        sage: P
        A 5-dimensional polyhedron in QQ^6 defined as the convex hull of 7 vertices
        sage: P.dim()
        5
        sage: P.Vrepresentation()
        (A vertex at (31, 0, 0, 0, 0, 0), A vertex at (0, 0, 0, 0, 0, 31),
         A vertex at (0, 0, 0, 0, 31, 0), A vertex at (0, 0, 31/2, 0, 31/2, 0),
         A vertex at (0, 31/2, 31/2, 0, 0, 0), A vertex at (0, 31/2, 0, 0, 31/2, 0),
         A vertex at (0, 0, 0, 31/2, 31/2, 0))

    .. NOTE::

      * Once constructed, a ``Polyhedron`` object is immutable.
      * Although the option ``field=RDF`` allows numerical data to
        be used, it might not give the right answer for degenerate
        input data - the results can depend upon the tolerance
        setting of cdd.
    """
    # Clean up the arguments
    vertices = _make_listlist(vertices)
    rays     = _make_listlist(rays)
    lines    = _make_listlist(lines)
    ieqs     = _make_listlist(ieqs)
    eqns     = _make_listlist(eqns)

    got_Vrep = (len(vertices+rays+lines) > 0)
    got_Hrep = (len(ieqs+eqns) > 0)

    if got_Vrep and got_Hrep:
        raise ValueError('You cannot specify both H- and V-representation.')
    elif got_Vrep:
        deduced_ambient_dim = _common_length_of(vertices, rays, lines)[1]
    elif got_Hrep:
        deduced_ambient_dim = _common_length_of(ieqs, eqns)[1] - 1
    else:
        if ambient_dim is None:
            deduced_ambient_dim = 0
        else:
            deduced_ambient_dim = ambient_dim
        if base_ring is None:
            base_ring = ZZ

    # set ambient_dim
    if ambient_dim is not None and deduced_ambient_dim!=ambient_dim:
        raise ValueError('Ambient space dimension mismatch. Try removing the "ambient_dim" parameter.')
    ambient_dim = deduced_ambient_dim

    # figure out base_ring
    from sage.misc.flatten import flatten
    values = flatten(vertices+rays+lines+ieqs+eqns)
    if base_ring is not None:
        try:
            convert = not all(x.parent() is base_ring for x in values)
        except AttributeError:   # No x.parent() method?
            convert = True
    else:
        from sage.rings.integer import is_Integer
        from sage.rings.rational import is_Rational
        from sage.rings.real_double import is_RealDoubleElement
        if all(is_Integer(x) for x in values):
            if got_Vrep:
                base_ring = ZZ
            else:   # integral inequalities usually do not determine a latice polytope!
                base_ring = QQ
            convert=False
        elif all(is_Rational(x) for x in values):
            base_ring = QQ
            convert=False
        elif all(is_RealDoubleElement(x) for x in values):
            base_ring = RDF
            convert=False
        else:
            try:
                map(ZZ, values)
                if got_Vrep:
                    base_ring = ZZ
                else:
                    base_ring = QQ
                convert = True
            except TypeError:
                from sage.structure.sequence import Sequence
                values = Sequence(values)
                if QQ.has_coerce_map_from(values.universe()):
                    base_ring = QQ
                    convert = True
                else:
                    base_ring = RDF
                    convert = True

    # Add the origin if necesarry
    if got_Vrep and len(vertices)==0:
        vertices = [ [0]*ambient_dim ]

    # Specific backends can override the base_ring
    from sage.geometry.polyhedron.parent import Polyhedra
    parent = Polyhedra(base_ring, ambient_dim, backend=backend)
    base_ring = parent.base_ring()

    # Convert into base_ring if necessary
    def convert_base_ring(lstlst):
        return [ [base_ring(x) for x in lst] for lst in lstlst]
    Hrep = Vrep = None
    if got_Hrep:
        Hrep = [ieqs, eqns]
    if got_Vrep:
        Vrep = [vertices, rays, lines]

    # finally, construct the Polyhedron
    return parent(Vrep, Hrep, convert=convert)
예제 #11
0
파일: path.py 프로젝트: lairez/ore_algebra
    def __init__(self, point, dop=None, singular=None, **kwds):
        """
        INPUT:

        - ``singular``: can be set to True to force this point to be considered
          a singular point, even if this cannot be checked (e.g. because we only
          have an enclosure)

        TESTS::

            sage: from ore_algebra import *
            sage: from ore_algebra.analytic.path import Point
            sage: Dops, x, Dx = DifferentialOperators()
            sage: [Point(z, Dx)
            ....:  for z in [1, 1/2, 1+I, QQbar(I), RIF(1/3), CIF(1/3), pi,
            ....:  RDF(1), CDF(I), 0.5r, 0.5jr, 10r, QQbar(1), AA(1/3)]]
            [1, 1/2, I + 1, I, [0.333333333333333...], [0.333333333333333...],
            3.141592653589794?, ~1.0000, ~1.0000*I, ~0.50000, ~0.50000*I, 10,
            1, 1/3]
            sage: Point(sqrt(2), Dx).iv()
            [1.414...]
            sage: Point(RBF(0), (x-1)*x*Dx, singular=True).dist_to_sing()
            1.000000000000000
        """
        SageObject.__init__(self)

        from sage.rings.complex_double import ComplexDoubleField_class
        from sage.rings.complex_field import ComplexField_class
        from sage.rings.complex_interval_field import ComplexIntervalField_class
        from sage.rings.real_double import RealDoubleField_class
        from sage.rings.real_mpfi import RealIntervalField_class
        from sage.rings.real_mpfr import RealField_class

        point = sage.structure.coerce.py_scalar_to_element(point)
        try:
            parent = point.parent()
        except AttributeError:
            raise TypeError("unexpected value for point: " + repr(point))
        if isinstance(point, Point):
            self.value = point.value
        elif isinstance(parent, (RealBallField, ComplexBallField)):
            self.value = point
        elif isinstance(parent, number_field_base.NumberField):
            _, hom = good_number_field(point.parent())
            self.value = hom(point)
        elif QQ.has_coerce_map_from(parent):
            self.value = QQ.coerce(point)
        elif QQbar.has_coerce_map_from(parent):
            alg = QQbar.coerce(point)
            NF, val, hom = alg.as_number_field_element()
            if NF is QQ:
                self.value = QQ.coerce(val)  # parent may be ZZ
            else:
                embNF = number_field.NumberField(NF.polynomial(),
                                                 NF.variable_name(),
                                                 embedding=hom(NF.gen()))
                self.value = val.polynomial()(embNF.gen())
        elif isinstance(
                parent,
            (RealField_class, RealDoubleField_class, RealIntervalField_class)):
            self.value = RealBallField(point.prec())(point)
        elif isinstance(parent, (ComplexField_class, ComplexDoubleField_class,
                                 ComplexIntervalField_class)):
            self.value = ComplexBallField(point.prec())(point)
        elif parent is sage.symbolic.ring.SR:
            try:
                return self.__init__(point.pyobject(), dop)
            except TypeError:
                pass
            try:
                return self.__init__(QQbar(point), dop)
            except (TypeError, ValueError, NotImplementedError):
                pass
            try:
                self.value = RLF(point)
            except (TypeError, ValueError):
                self.value = CLF(point)
        else:
            try:
                self.value = RLF.coerce(point)
            except TypeError:
                self.value = CLF.coerce(point)

        parent = self.value.parent()
        assert (isinstance(
            parent,
            (number_field_base.NumberField, RealBallField, ComplexBallField))
                or parent is RLF or parent is CLF)

        if dop is None:  # TBI
            if isinstance(point, Point):
                self.dop = point.dop
        else:
            self.dop = DifferentialOperator(dop.numerator())
        self._force_singular = bool(singular)
        self.options = kwds