From bb7e9eb83b65636cfc6de1315ed1a4e0a8cd852a Mon Sep 17 00:00:00 2001
From: Abivarman <abivarman.kandiah@etu.hesge.ch>
Date: Tue, 14 Dec 2021 11:40:57 +0100
Subject: [PATCH] Compute_lagrange fonctionnel
---
polynome.py | 4 ++--
reed_solomon.py | 12 ++++--------
2 files changed, 6 insertions(+), 10 deletions(-)
diff --git a/polynome.py b/polynome.py
index 843614b..2f8be27 100644
--- a/polynome.py
+++ b/polynome.py
@@ -38,7 +38,7 @@ class polynome():
coeff_poly_res = [0] * (len(self.coefs) + len(poly_2.coefs) - 1)
for index_1, value_1 in enumerate(self.coefs):
for index_2, value_2 in enumerate(poly_2.coefs):
- coeff_poly_res[index_1 + index_2] += value_1 * value_2 % self.prime_mod
+ coeff_poly_res[index_1 + index_2] += (value_1 * value_2) % self.prime_mod
return polynome(coeff_poly_res)
def evaluate(self, x):
@@ -46,4 +46,4 @@ class polynome():
res = 0
for i in range(len(self.coefs) - 1, -1, -1):
res = (res * x + self.coefs[i])
- return res % self.prime_mod
+ return (res % self.prime_mod)
diff --git a/reed_solomon.py b/reed_solomon.py
index c40a79a..e905c4d 100644
--- a/reed_solomon.py
+++ b/reed_solomon.py
@@ -29,12 +29,8 @@ def lagrange_compute(l: list) -> polynome:
poly_n = polynome([1])
for x_k, y_k in enumerate(l):
if x_k != x_i:
- #print(f"value : {x_i - x_k}")
- d = inverse_mult(x_i-x_k, poly_n.prime_mod)
- #print(f"inverse : {d}")
- #poly_n = poly_n.mul(polynome([-x_k / (x_i-x_k), 1 / (x_i-x_k)]))
+ d = inverse_mult((x_i-x_k) % poly_n.prime_mod, poly_n.prime_mod)
poly_n = poly_n.mul(polynome([-x_k * d % poly_n.prime_mod, d % poly_n.prime_mod]))
- #poly_n.show()
poly_n = poly_n.mul(polynome([y_i[1] % poly_n.prime_mod]))
poly = poly.add(poly_n)
return poly
@@ -43,7 +39,7 @@ def check_nb_error(l: list, p: polynome) -> int:
pass
if __name__ == '__main__':
- list_ = [(0, 2), (1, 4), (2, 8)]
+ list_ = [(0, 0), (1, 1), (2, 2)]
poly = lagrange_compute(list_)
- poly.show()
- print(poly.evaluate(1))
+ #poly.show()
+ print(poly.evaluate(5))
--
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