示例#1
0
    def analyze(self, expr):
        """Rewrite an expression as sorted list of terms. """
        gens, terms = set([]), []

        for term in expr.as_Add():
            coeff, cpart, ncpart = [], {}, []

            for factor in term.as_Mul():
                if not factor.is_commutative:
                    ncpart.append(factor)
                else:
                    if factor.is_Number:
                        coeff.append(factor)
                    else:
                        base, exp = _analyze_power(*factor.as_Pow())

                        cpart[base] = exp
                        gens.add(base)

            terms.append((coeff, cpart, ncpart, term))

        gens = sorted(gens, Basic._compare_pretty)

        k, indices = len(gens), {}

        for i, g in enumerate(gens):
            indices[g] = i

        result = []

        for coeff, cpart, ncpart, term in terms:
            monom = [0] * k

            for base, exp in cpart.iteritems():
                monom[indices[base]] = exp

            result.append((coeff, monom, ncpart, term))

        if self.order is None:
            return sorted(result, Basic._compare_pretty)
        else:
            return sorted(result, self._compare_terms)
示例#2
0
文件: printer.py 项目: tovrstra/sympy
    def analyze(self, expr):
        """Rewrite an expression as sorted list of terms. """
        gens, terms = set([]), []

        for term in expr.as_Add():
            coeff, cpart, ncpart = [], {}, []

            for factor in term.as_Mul():
                if not factor.is_commutative:
                    ncpart.append(factor)
                else:
                    if factor.is_Number:
                        coeff.append(factor)
                    else:
                        base, exp = _analyze_power(*factor.as_Pow())

                        cpart[base] = exp
                        gens.add(base)

            terms.append((coeff, cpart, ncpart, term))

        gens = sorted(gens, Basic._compare_pretty)

        k, indices = len(gens), {}

        for i, g in enumerate(gens):
            indices[g] = i

        result = []

        for coeff, cpart, ncpart, term in terms:
            monom = [0] * k

            for base, exp in cpart.iteritems():
                monom[indices[base]] = exp

            result.append((coeff, monom, ncpart, term))

        if self.order is None:
            return sorted(result, Basic._compare_pretty)
        else:
            return sorted(result, self._compare_terms)
示例#3
0
def test__analyze_power():
    assert _analyze_power(x, S(1)) == (x, S(1))
    assert _analyze_power(x, S(2)) == (x, S(2))
    assert _analyze_power(x, -S(1)) == (x**(-1), S(1))
    assert _analyze_power(x, -S(2)) == (x**(-1), S(2))

    assert _analyze_power(x, S(1) / 3) == (x**(S(1) / 3), S(1))
    assert _analyze_power(x, S(2) / 3) == (x**(S(1) / 3), S(2))
    assert _analyze_power(x, -S(1) / 3) == (x**(-S(1) / 3), S(1))
    assert _analyze_power(x, -S(2) / 3) == (x**(-S(1) / 3), S(2))

    assert _analyze_power(x, y) == (x**y, S(1))
    assert _analyze_power(x, -y) == (x**(-y), S(1))
    assert _analyze_power(x, 2 * y) == (x**y, S(2))
    assert _analyze_power(x, -2 * y) == (x**(-y), S(2))

    assert _analyze_power(x, y / 3) == (x**(y / 3), S(1))
    assert _analyze_power(x, -y / 3) == (x**(-y / 3), S(1))
    assert _analyze_power(x, 2 * y / 3) == (x**(y / 3), S(2))
    assert _analyze_power(x, -2 * y / 3) == (x**(-y / 3), S(2))

    assert _analyze_power(x, S(1.0)) == (x**S(1.0), S(1))
    assert _analyze_power(x, S(2.0)) == (x**S(2.0), S(1))
    assert _analyze_power(x, -S(1.0)) == (x**(-S(1.0)), S(1))
    assert _analyze_power(x, -S(2.0)) == (x**(-S(2.0)), S(1))

    assert _analyze_power(x, S(1.0) * y) == (x**(S(1.0) * y), S(1))
    assert _analyze_power(x, S(2.0) * y) == (x**(S(2.0) * y), S(1))
    assert _analyze_power(x, -S(1.0) * y) == (x**(-S(1.0) * y), S(1))
    assert _analyze_power(x, -S(2.0) * y) == (x**(-S(2.0) * y), S(1))
示例#4
0
def test__analyze_power():
    assert _analyze_power(x, S(1)) == (x, S(1))
    assert _analyze_power(x, S(2)) == (x, S(2))
    assert _analyze_power(x, -S(1)) == (x**(-1), S(1))
    assert _analyze_power(x, -S(2)) == (x**(-1), S(2))

    assert _analyze_power(x, S(1)/3) == (x**(S(1)/3), S(1))
    assert _analyze_power(x, S(2)/3) == (x**(S(1)/3), S(2))
    assert _analyze_power(x, -S(1)/3) == (x**(-S(1)/3), S(1))
    assert _analyze_power(x, -S(2)/3) == (x**(-S(1)/3), S(2))

    assert _analyze_power(x, y) == (x**y, S(1))
    assert _analyze_power(x, -y) == (x**(-y), S(1))
    assert _analyze_power(x, 2*y) == (x**y, S(2))
    assert _analyze_power(x, -2*y) == (x**(-y), S(2))

    assert _analyze_power(x, y/3) == (x**(y/3), S(1))
    assert _analyze_power(x, -y/3) == (x**(-y/3), S(1))
    assert _analyze_power(x, 2*y/3) == (x**(y/3), S(2))
    assert _analyze_power(x, -2*y/3) == (x**(-y/3), S(2))

    assert _analyze_power(x, S(1.0)) == (x**S(1.0), S(1))
    assert _analyze_power(x, S(2.0)) == (x**S(2.0), S(1))
    assert _analyze_power(x, -S(1.0)) == (x**(-S(1.0)), S(1))
    assert _analyze_power(x, -S(2.0)) == (x**(-S(2.0)), S(1))

    assert _analyze_power(x, S(1.0)*y) == (x**(S(1.0)*y), S(1))
    assert _analyze_power(x, S(2.0)*y) == (x**(S(2.0)*y), S(1))
    assert _analyze_power(x, -S(1.0)*y) == (x**(-S(1.0)*y), S(1))
    assert _analyze_power(x, -S(2.0)*y) == (x**(-S(2.0)*y), S(1))