def as_leading_term(self, *symbols): """ Returns the leading term. Example: >>> from sympy.abc import x >>> (1+x+x**2).as_leading_term(x) 1 >>> (1/x**2+x+x**2).as_leading_term(x) x**(-2) Note: self is assumed to be the result returned by Basic.series(). """ from sympy import powsimp if len(symbols)>1: c = self for x in symbols: c = c.as_leading_term(x) return c elif not symbols: return self x = sympify(symbols[0]) assert x.is_Symbol, `x` if not self.has(x): return self obj = self._eval_as_leading_term(x) if obj is not None: return powsimp(obj, deep=True, combine='exp') raise NotImplementedError('as_leading_term(%s, %s)' % (self, x))
def as_leading_term(self, *symbols): if len(symbols)>1: c = self for x in symbols: c = c.as_leading_term(x) return c elif not symbols: return self x = Basic.sympify(symbols[0]) assert isinstance(x, Basic.Symbol),`x` if not self.has(x): return self expr = self.expand(trig=True) obj = expr._eval_as_leading_term(x) if obj is not None: return obj raise NotImplementedError('as_leading_term(%s, %s)' % (self, x))