示例#1
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    def __new__(cls, label, range=None, **kw_args):
        from diofant.utilities.misc import filldedent

        if isinstance(label, str):
            label = Symbol(label, integer=True)
        label, range = list(map(sympify, (label, range)))

        if not label.is_integer:
            raise TypeError("Idx object requires an integer label.")

        elif is_sequence(range):
            if len(range) != 2:
                raise ValueError(
                    filldedent("""
                    Idx range tuple must have length 2, but got %s""" %
                               len(range)))
            for bound in range:
                if not (bound.is_integer or abs(bound) is S.Infinity):
                    raise TypeError("Idx object requires integer bounds.")
            args = label, Tuple(*range)
        elif isinstance(range, Expr):
            if not (range.is_integer or range is S.Infinity):
                raise TypeError("Idx object requires an integer dimension.")
            args = label, Tuple(0, range - 1)
        elif range:
            raise TypeError(
                filldedent("""
                The range must be an ordered iterable or
                integer Diofant expression."""))
        else:
            args = label,

        obj = Expr.__new__(cls, *args, **kw_args)
        return obj
示例#2
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    def _new(cls, poly, func, auto=True):
        """Construct new raw ``RootSum`` instance. """
        obj = Expr.__new__(cls)

        obj.poly = poly
        obj.fun = func
        obj.auto = auto

        return obj
示例#3
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    def __new__(cls, label, shape=None, **kw_args):
        if isinstance(label, str):
            label = Symbol(label)
        elif isinstance(label, (Dummy, Symbol)):
            pass
        else:
            raise TypeError("Base label should be a string or Symbol.")

        obj = Expr.__new__(cls, label, **kw_args)
        if is_sequence(shape):
            obj._shape = Tuple(*shape)
        else:
            obj._shape = sympify(shape)
        return obj
示例#4
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    def __new__(cls, base, *args, **kw_args):
        from diofant.utilities.misc import filldedent

        if not args:
            raise IndexException("Indexed needs at least one index.")
        if isinstance(base, (str, Symbol)):
            base = IndexedBase(base)
        elif not hasattr(base, '__getitem__') and not isinstance(
                base, IndexedBase):
            raise TypeError(
                filldedent("""
                Indexed expects string, Symbol or IndexedBase as base."""))
        args = list(map(sympify, args))
        return Expr.__new__(cls, base, *args, **kw_args)
示例#5
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    def _new(cls, poly, index):
        """Construct new ``RootOf`` object from raw data. """
        obj = Expr.__new__(cls)

        obj.poly = PurePoly(poly)
        obj.index = index

        try:
            _reals_cache[obj.poly] = _reals_cache[poly]
            _complexes_cache[obj.poly] = _complexes_cache[poly]
        except KeyError:
            pass

        return obj
示例#6
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    def __new__(cls, e, z, z0, dir="+"):
        e = sympify(e)
        z = sympify(z)
        z0 = sympify(z0)

        if z0 is S.Infinity:
            dir = "-"
        elif z0 is S.NegativeInfinity:
            dir = "+"

        if isinstance(dir, str):
            dir = Symbol(dir)
        elif not isinstance(dir, Symbol):
            raise TypeError("direction must be of type str or Symbol, not %s" %
                            type(dir))
        if str(dir) not in ('+', '-', 'real'):
            raise ValueError(
                "direction must be either '+' or '-' or 'real', not %s" % dir)

        obj = Expr.__new__(cls)
        obj._args = (e, z, z0, dir)
        return obj
示例#7
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 def _hashable_content(self):
     return Expr._hashable_content(self) + (self._shape, )
示例#8
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    def __new__(cls, expr, *args, **kwargs):
        expr = sympify(expr)

        if not args:
            if expr.is_Order:
                variables = expr.variables
                point = expr.point
            else:
                variables = list(expr.free_symbols)
                point = [S.Zero]*len(variables)
        else:
            args = list(args if is_sequence(args) else [args])
            variables, point = [], []
            if is_sequence(args[0]):
                for a in args:
                    v, p = list(map(sympify, a))
                    variables.append(v)
                    point.append(p)
            else:
                variables = list(map(sympify, args))
                point = [S.Zero]*len(variables)

        if not all(isinstance(v, (Dummy, Symbol)) for v in variables):
            raise TypeError('Variables are not symbols, got %s' % variables)

        if len(list(uniq(variables))) != len(variables):
            raise ValueError('Variables are supposed to be unique symbols, got %s' % variables)

        if expr.is_Order:
            expr_vp = dict(expr.args[1:])
            new_vp = dict(expr_vp)
            vp = dict(zip(variables, point))
            for v, p in vp.items():
                if v in new_vp.keys():
                    if p != new_vp[v]:
                        raise NotImplementedError(
                            "Mixing Order at different points is not supported.")
                else:
                    new_vp[v] = p
            if set(expr_vp.keys()) == set(new_vp.keys()):
                return expr
            else:
                variables = list(new_vp.keys())
                point = [new_vp[v] for v in variables]

        if expr is S.NaN:
            return S.NaN

        if any(x in p.free_symbols for x in variables for p in point):
            raise ValueError('Got %s as a point.' % point)

        if variables:
            if any(p != point[0] for p in point):
                raise NotImplementedError
            if point[0] in [S.Infinity, S.NegativeInfinity]:
                s = {k: 1/Dummy() for k in variables}
                rs = {1/v: 1/k for k, v in s.items()}
            elif point[0] is not S.Zero:
                s = {k: Dummy() + point[0] for k in variables}
                rs = {v - point[0]: k - point[0] for k, v in s.items()}
            else:
                s = ()
                rs = ()

            expr = expr.subs(s)

            if expr.is_Add:
                from diofant import expand_multinomial
                expr = expand_multinomial(expr)

            if s:
                args = tuple(r[0] for r in rs.items())
            else:
                args = tuple(variables)

            if len(variables) > 1:
                # XXX: better way?  We need this expand() to
                # workaround e.g: expr = x*(x + y).
                # (x*(x + y)).as_leading_term(x, y) currently returns
                # x*y (wrong order term!).  That's why we want to deal with
                # expand()'ed expr (handled in "if expr.is_Add" branch below).
                expr = expr.expand()

            if expr.is_Add:
                lst = expr.extract_leading_order(args)
                expr = Add(*[f.expr for (e, f) in lst])

            elif expr:
                expr = expr.as_leading_term(*args)
                expr = expr.as_independent(*args, as_Add=False)[1]

                expr = expand_power_base(expr)
                expr = expand_log(expr)

                if len(args) == 1:
                    # The definition of O(f(x)) symbol explicitly stated that
                    # the argument of f(x) is irrelevant.  That's why we can
                    # combine some power exponents (only "on top" of the
                    # expression tree for f(x)), e.g.:
                    # x**p * (-x)**q -> x**(p+q) for real p, q.
                    x = args[0]
                    margs = list(Mul.make_args(
                        expr.as_independent(x, as_Add=False)[1]))

                    for i, t in enumerate(margs):
                        if t.is_Pow:
                            b, q = t.args
                            if b in (x, -x) and q.is_extended_real and not q.has(x):
                                margs[i] = x**q
                            elif b.is_Pow and not b.exp.has(x):
                                b, r = b.args
                                if b in (x, -x) and r.is_extended_real:
                                    margs[i] = x**(r*q)
                            elif b.is_Mul and b.args[0] is S.NegativeOne:
                                b = -b
                                if b.is_Pow and not b.exp.has(x):
                                    b, r = b.args
                                    if b in (x, -x) and r.is_extended_real:
                                        margs[i] = x**(r*q)

                    expr = Mul(*margs)

            expr = expr.subs(rs)

        if expr is S.Zero:
            return expr

        if expr.is_Order:
            expr = expr.expr

        if not expr.has(*variables):
            expr = S.One

        # create Order instance:
        vp = dict(zip(variables, point))
        variables.sort(key=default_sort_key)
        point = [vp[v] for v in variables]
        args = (expr,) + Tuple(*zip(variables, point))
        obj = Expr.__new__(cls, *args)
        return obj