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Connor 2018-09-11 14:03:16 -07:00 committed by GitHub
parent 248a9c0305
commit dfe69c396f
1 changed files with 2 additions and 9 deletions
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9
ac_encode.py
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@ -27,8 +27,6 @@ def encode(string, c0=BETA0, c1=BETA1, adaptive=True):
b = ONE b = ONE
a = 0 a = 0
tot0 = 0
tot1 = 0
if not adaptive: if not adaptive:
p0 = c0 / (c0 + c1) p0 = c0 / (c0 + c1)
ans = "" ans = ""
@ -54,12 +52,10 @@ def encode(string, c0=BETA0, c1=BETA1, adaptive=True):
if c == '1': if c == '1':
a = boundary a = boundary
tot1 += 1
if adaptive: if adaptive:
c1 += 1 c1 += 1
elif c == '0': elif c == '0':
b = boundary b = boundary
tot0 += 1
if adaptive: if adaptive:
c0 += 1 c0 += 1
# ignore other characters # ignore other characters
@ -116,8 +112,6 @@ def decode(string, N, c0=BETA0, c1=BETA1, adaptive=True):
b = ONE b = ONE
a = 0 a = 0
tot0 = 0
tot1 = 0
model_needs_updating = True model_needs_updating = True
if not adaptive: if not adaptive:
p0 = c0 / (c0 + c1) p0 = c0 / (c0 + c1)
@ -129,6 +123,7 @@ def decode(string, N, c0=BETA0, c1=BETA1, adaptive=True):
if N <= 0: if N <= 0:
break # out of the string-reading loop break # out of the string-reading loop
assert N > 0 assert N > 0
# (u,v) is the current "encoded alphabet" binary interval, # (u,v) is the current "encoded alphabet" binary interval,
# and halfway is its midpoint. # and halfway is its midpoint.
# (a,b) is the current "source alphabet" interval, # (a,b) is the current "source alphabet" interval,
@ -161,7 +156,6 @@ def decode(string, N, c0=BETA0, c1=BETA1, adaptive=True):
if boundary <= u: if boundary <= u:
ans += "1" ans += "1"
tot1 += 1
if adaptive: if adaptive:
c1 += 1 c1 += 1
a = boundary a = boundary
@ -169,7 +163,6 @@ def decode(string, N, c0=BETA0, c1=BETA1, adaptive=True):
N -= 1 N -= 1
elif boundary >= v: elif boundary >= v:
ans += "0" ans += "0"
tot0 += 1
if adaptive: if adaptive:
c0 += 1 c0 += 1
b = boundary b = boundary