openpilot/selfdrive/locationd/kalman/helpers/chi2_lookup.py

23 lines
508 B
Python

import os
import numpy as np
def gen_chi2_ppf_lookup(max_dim=200):
from scipy.stats import chi2
table = np.zeros((max_dim, 98))
for dim in range(1, max_dim):
table[dim] = chi2.ppf(np.arange(.01, .99, .01), dim)
np.save('chi2_lookup_table', table)
def chi2_ppf(p, dim):
table = np.load(os.path.dirname(os.path.realpath(__file__)) + '/chi2_lookup_table.npy')
result = np.interp(p, np.arange(.01, .99, .01), table[dim])
return result
if __name__ == "__main__":
gen_chi2_ppf_lookup()