def to_rational(ctx, s, limit=True): p, q = to_rational(s._mpf_) if not limit or q <= ctx.max_denom: return p, q p0, q0, p1, q1 = 0, 1, 1, 0 n, d = p, q while True: a = n//d q2 = q0 + a*q1 if q2 > ctx.max_denom: break p0, q0, p1, q1 = p1, q1, p0 + a*p1, q2 n, d = d, n - a*d k = (ctx.max_denom - q0)//q1 number = mpq(p, q) bound1 = mpq(p0 + k*p1, q0 + k*q1) bound2 = mpq(p1, q1) if not bound2 or not bound1: return p, q elif abs(bound2 - number) <= abs(bound1 - number): return bound2._mpq_ else: return bound1._mpq_
def to_rational(ctx, s, limit=True): p, q = to_rational(s._mpf_) if not limit or q <= ctx.max_denom: return p, q p0, q0, p1, q1 = 0, 1, 1, 0 n, d = p, q while True: a = n//d q2 = q0 + a*q1 if q2 > ctx.max_denom: break p0, q0, p1, q1 = p1, q1, p0 + a*p1, q2 n, d = d, n - a*d k = (ctx.max_denom - q0)//q1 number = mpq(p, q) bound1 = mpq(p0 + k*p1, q0 + k*q1) bound2 = mpq(p1, q1) if not bound2 or not bound1: return p, q elif abs(bound2 - number) <= abs(bound1 - number): return bound2._mpq_ else: return bound1._mpq_