import numpy as np
from gauss import solve

a = np.array([[1, 1.0 / 4,  0, 0],
              [1, 5.0 / 4, 12, 0],
              [1, 1.0 / 3,  1, 1],
              [1, 5.0 / 4, 13, 1]])
b = np.array([0, 0, 1e16, 0])
x_gauss = solve(a, b)
x = np.array([-3e16, 1.2e17, -1e16, 1e16])
print "Norme de l'erreur (pivot partiel) :", np.linalg.norm(x - x_gauss)