channel add noise

Code/ldpc/src/channel.rs

@@ -1,4 +1,6 @@
-pub rand::Rng;
+use std::usize;
+
+use rand::{Rng, RngExt};
 
 pub struct Channel {
     pub error_prob: f64,
@@ -7,8 +9,24 @@ pub struct Channel {
 impl Channel {
     pub fn new(error_prob: f64) -> Self {
         assert!(error_prob >= 0.0 && error_prob <= 1.0, "0 <= p <= 1");
-        Self {error_prob}
+        Self { error_prob }
     }
 
-}
+    pub fn add_noise(&self, input: &[u8]) -> Vec<u8> {
+        let mut rng = rand::rng();
+        let mut out = input.to_vec();
 
+        for b in out.iter_mut() {
+            let r_v: f64 = rng.random_range(0.0..1.0);
+            if r_v < self.error_prob {
+                *b ^= 1;
+            }
+        }
+        out
+    }
+
+    pub fn count_errors(original: &[u8], other: &[u8]) -> usize {
+        assert_eq!(original.len(), other.len(), "Slice pas de la même taille");
+        original.iter().zip(other).filter(|(a, b)| a != b).count()
+    }
+}