func_tools.py 文件源码

def _nearest_pow_2(x):
    """
    Find power of two nearest to x
    >>> _nearest_pow_2(3)
    2.0
    >>> _nearest_pow_2(15)
    16.0
    :type x: float
    :param x: Number
    :rtype: Int
    :return: Nearest power of 2 to x
    """
    a = M.pow(2, M.ceil(np.log2(x)))
    b = M.pow(2, M.floor(np.log2(x)))
    if abs(a - x) < abs(b - x):
        return a
    else:
        return b