Python Poly.factor方法代码示例

# 需要导入模块: from sympy.polys import Poly [as 别名]
# 或者: from sympy.polys.Poly import factor [as 别名]
    def doit(self, **hints):
        """
        Perform the integration using any hints given.

        Examples
        ========

        >>> from sympy import Integral
        >>> from sympy.abc import x, i
        >>> Integral(x**i, (i, 1, 3)).doit()
        Piecewise((2, Eq(log(x), 0)), (x**3/log(x) - x/log(x), True))

        See Also
        ========

        sympy.integrals.trigonometry.trigintegrate
        sympy.integrals.risch.heurisch
        sympy.integrals.rationaltools.ratint
        as_sum : Approximate the integral using a sum
        """
        if not hints.get('integrals', True):
            return self

        deep = hints.get('deep', True)
        meijerg = hints.get('meijerg', None)
        conds = hints.get('conds', 'piecewise')
        risch = hints.get('risch', None)
        manual = hints.get('manual', None)

        if conds not in ['separate', 'piecewise', 'none']:
            raise ValueError('conds must be one of "separate", "piecewise", '
                             '"none", got: %s' % conds)

        if risch and any(len(xab) > 1 for xab in self.limits):
            raise ValueError('risch=True is only allowed for indefinite integrals.')

        # check for the trivial zero
        if self.is_zero:
            return S.Zero

        # now compute and check the function
        function = self.function
        if deep:
            function = function.doit(**hints)
        if function.is_zero:
            return S.Zero

        # There is no trivial answer, so continue

        undone_limits = []
        # ulj = free symbols of any undone limits' upper and lower limits
        ulj = set()
        for xab in self.limits:
            # compute uli, the free symbols in the
            # Upper and Lower limits of limit I
            if len(xab) == 1:
                uli = set(xab[:1])
            elif len(xab) == 2:
                uli = xab[1].free_symbols
            elif len(xab) == 3:
                uli = xab[1].free_symbols.union(xab[2].free_symbols)
            # this integral can be done as long as there is no blocking
            # limit that has been undone. An undone limit is blocking if
            # it contains an integration variable that is in this limit's
            # upper or lower free symbols or vice versa
            if xab[0] in ulj or any(v[0] in uli for v in undone_limits):
                undone_limits.append(xab)
                ulj.update(uli)
                function = self.func(*([function] + [xab]))
                factored_function = function.factor()
                if not isinstance(factored_function, Integral):
                    function = factored_function
                continue

            # There are a number of tradeoffs in using the Meijer G method.
            # It can sometimes be a lot faster than other methods, and
            # sometimes slower. And there are certain types of integrals for
            # which it is more likely to work than others.
            # These heuristics are incorporated in deciding what integration
            # methods to try, in what order.
            # See the integrate() docstring for details.
            def try_meijerg(function, xab):
                ret = None
                if len(xab) == 3 and meijerg is not False:
                    x, a, b = xab
                    try:
                        res = meijerint_definite(function, x, a, b)
                    except NotImplementedError:
                        from sympy.integrals.meijerint import _debug
                        _debug('NotImplementedError from meijerint_definite')
                        res = None
                    if res is not None:
                        f, cond = res
                        if conds == 'piecewise':
                            ret = Piecewise((f, cond),
                                          (self.func(function, (x, a, b)), True))
                        elif conds == 'separate':
                            if len(self.limits) != 1:
                                raise ValueError('conds=separate not supported in '
                                                 'multiple integrals')
#.........这里部分代码省略.........