5
limit_denominator(max_denominator=1000000)
Finds and returns the closest Fraction to self that has denominator at most max_denominator. This method is useful for finding rational approximations to a given floating-point number:
>>>
>>> from fractions import Fraction
>>> Fraction('3.1415926535897932').limit_denominator(1000)
Fraction(355, 113)
它不應該像嘗試/ 999,b/998,c/997 ..並找到最佳近似值。python的fractions.limit_denominator是如何實現的?
看起來像一個二分查找,在「最佳下限」和「最佳上限」近似值之間擠壓x –