ac_encode.py

@@ -30,7 +30,7 @@ def encode(string, c0=BETA0, c1=BETA1, adaptive=True):
     tot0 = 0
     tot1 = 0
     if not adaptive:
-        p0 = c0 * 1 / (c0 + c1)
+        p0 = c0 / (c0 + c1)
     ans = ""
     charstack = [0]  # how many undecided characters remain to print
 
@@ -38,7 +38,7 @@ def encode(string, c0=BETA0, c1=BETA1, adaptive=True):
         w = b - a
         if adaptive:
             cT = c0 + c1
-            p0 = c0 * 1 / cT
+            p0 = c0 / cT
         boundary = a + int(p0 * w)
 
         # these warnings mean that some of the probabilities
@@ -109,7 +109,7 @@ def encode(string, c0=BETA0, c1=BETA1, adaptive=True):
     return ans
 
 
-def decode(string, N=10000, c0=BETA0, c1=BETA1, adaptive=True):
+def decode(string, N, c0=BETA0, c1=BETA1, adaptive=True):
     # must supply N, the number of source characters remaining.
     assert c0 > 0
     assert c1 > 0
@@ -120,7 +120,7 @@ def decode(string, N=10000, c0=BETA0, c1=BETA1, adaptive=True):
     tot1 = 0
     model_needs_updating = True
     if not adaptive:
-        p0 = c0 * 1 / (c0 + c1)
+        p0 = c0 / (c0 + c1)
     ans = ""
 
     u = 0
@@ -145,12 +145,11 @@ def decode(string, N=10000, c0=BETA0, c1=BETA1, adaptive=True):
         # Then emulate the encoder's computations,
         # and tie (u,v) to tag along for the ride.
         while 1:  # do-while
-            firsttime = 0
             if model_needs_updating:
                 w = b - a
                 if adaptive:
                     cT = c0 + c1
-                    p0 = c0 * 1 / cT
+                    p0 = c0 / cT
                 boundary = a + int(p0 * w)
                 if boundary == a:
                     boundary += 1