correction du code

455-Codage_Sources/algo_code/code_arithmetique.py

@@ -2,28 +2,78 @@
 
 import numpy as np
 
-
+N=10
-p_s = [0.1,0.9]
+p = 0.2
 P = np.random.rand(N)
-X =  [0 for p in P if p > p_s[0] else 1]
+X = np.zeros(N,dtype='int')
+for i in range(N):
+    if P[i] > p:
+        X[i] = 1
 
+X=[0,1,0,0,1,0,0,0,0,0]
+print(X)
 
-def binary(n,b=2,m):
+def binary(n,m,b=2):
     """
     Convertie un nombre décimal en sa version binaire tronqué à m bits.
     """
-    return np.ceil(n*b**m)
+    binaire= np.floor(n*b**m) # on se décale dans les entiers et on floor
 
-def arithm(X):
+    return binaire,np.binary_repr(int(binaire))
+
+def arithm(X,p):
     l=[0]
     h= [1]
     for x in X:
         if x == 0:
-            h.append(l[-1]+p_s[0]*(h[-1]-l[-1]))
+            h.append(l[-1]+p*(h[-1]-l[-1]))
             l.append(l[-1])
         else:
-            l.append(l[-1]+p_s[0]*(h[-1]-l[-1]))
+            l.append(l[-1]+p*(h[-1]-l[-1]))
             h.append(h[-1])
 
             lmb = (l[-1]+h[-1])/2
+
             mu = int(-np.log2(h[-1]-l[-1]))+1
+    code = binary(lmb,mu)
+    return code,lmb,mu
+
+def arithm_pratique(X,p):
+    l = [0]                     # borne inférieur
+    h =[1]                      # borne supérieur
+    f = 0                       # follow
+    c =[]                       # code
+    for k in range(len(X)):
+        print("for loop")
+        if X[k] == 0:
+            l.append(l[-1])
+            h.append(l[-1]+p*(h[-1]-l[-1]))
+        else:
+           l.append(l[-1]+p*(h[-1]-l[-1]))
+           h.append(h[-1])
+        print(X[k])
+        print(l[-3:])
+        print(h[-3:])
+        while ((l[-1]>=0 and h[-1]<0.5)
+            or (l[-1]>=0.5 and h[-1]<1)
+            or (l[-1]>= 0.25 and h[-1]<0.75)):
+            print(" loop")
+            if (l[-1]>=0 and h[-1]<0.5):
+                print("  case 1")
+                c += [0]+[1]*f
+                l[-1] *=2
+                h[-1] *=2
+            elif (l[-1]>=0.5 and h[-1]<1):
+                print("  case 2")
+                c += [1]+[0]*f
+                l[-1] = 2*l[-1]-1
+                h[-1] = 2*h[-1]-1
+            elif (l[-1]>= 0.25 and h[-1]<0.75):
+                print("  case 3")
+                f +=1
+                l[-1] = 2*l[-1]-0.5
+                h[-1] = 2*h[-1]-0.5
+    return c
+
+#print(arithm(X,p))
+print(arithm_pratique(X,p))