def is_in_range(a, b, radius):
    """Determine if two points are within a defined radius of each other.
    
    Arguments:
        a (tuple): The x and y coordinates of the first point.
        b (tuple): The x and y coordinates of the second point.
        radius (tuple): The maximum distance between the two points that can be
            considered within the range of acceptability. 
    
    Returns:
        bool: True if either point is within the given radius of the other,
            otherwise False.

    Examples:
        >>> is_in_range((1,1), (0, 0), 1.5)
        True
        >>> is_in_range((3,3), (1, 1), 1)
        False
        >>> is_in_range((5,2), (-3, 4), 11)
        True
    """
    return all(map(lambda p: abs(p[0] - p[1]) < radius, zip(a, b)))
