#convert number of sigmas to the false probability
#by Zhiqi Huang (huangzhq25@mail.sysu.edu.cn)
import numpy as np
from scipy.special import erfc

def sigma_to_prob(n_sigma):
    return erfc(n_sigma/np.sqrt(2.))


n_sigma = 2.2222
print(n_sigma, " sigma confidence level: false probability = ", sigma_to_prob(n_sigma))