使用numpy数组计算两类点中两两之间的L2距离

def array_distance(arr1, arr2):
    '''
    计算两个数组里，每任意两个点之间的L2距离
    arr1 和 arr2 都必须是numpy数组
    且维度分别为 m x 2, n x 2
    输出数组的维度为 m x n
    '''
    m, _ = arr1.shape
    n, _ = arr2.shape
    arr1_power = np.power(arr1, 2)
    arr1_power_sum = arr1_power[:, 0] + arr1_power[:, 1]
    arr1_power_sum = np.tile(arr1_power_sum, (n, 1))
    arr1_power_sum = arr1_power_sum.T
    arr2_power = np.power(arr2, 2)
    arr2_power_sum = arr2_power[:, 0] + arr2_power[:, 1]
    arr2_power_sum = np.tile(arr2_power_sum, (m, 1))
    dis = arr1_power_sum + arr2_power_sum - (2 * np.dot(arr1, arr2.T))
    return dis