what's the meaning of compare function

[`get_prob function`](https://github.com/nvlong21/Face_Recognize/blob/d01ecf25b5e29d28edf53af93219c7f1805ef308/utils/utils.py#L170)
could you tell me what's the meaning of the get_prob function, and the meaning of the parameters:mu_0, sigma_0, mu_1, sigma_1