我正在嘗試使用 Python 中的類來模擬馬爾可夫鏈。這是我的代碼：import random...class Chain: def __init__(self, probabilities, start): self.probs = probabilities self.start = start self.names = list(self.probs.keys()) def __iter__(self): self.pos = self.start return self def __next__(self): self.random_num = random.randrange(100) prob_l = self.probs[self.pos] for ind, prob in enumerate(prob_l): self.prob_sum += prob if self.random_num < self.prob_sum: exclude_names = self.names[:ind] + self.names[ind + 1 :] self.prob_sum = 0 self.pos = exclude_names[ind] return self.pos return self.poschain = Chain({"A": [50, 25], "B": [50, 25], "C": [50, 50]}, "A")chain_iter = iter(chain)for k in range(100): print(next(chain_iter))它按預期工作，但有時會重復字母 C。由于字典中的兩個 50，它應該有 50/50 的機會轉到 A 或 B。它不應該重復。
1 回答
DIEA
TA貢獻1820條經驗 獲得超2個贊
您會看到重復的 C，因為當前節點的索引未正確計算。
這是帶有注釋的更新代碼：
class Chain:
def __init__(self, probabilities, start): # only called once
self.probs = probabilities
self.start = start
self.names = list(self.probs.keys())
def __iter__(self): # only called once
return self
def __next__(self): # each iteration
import random
self.pos = self.start # next step
self.random_num = random.randrange(100) # choice percentile must be in here
i = self.names.index(self.pos) # get index of this node in big list
prob_l = self.probs[self.pos] # get probs
self.prob_sum = 0 # start prob scan
for ind, prob in enumerate(prob_l): # probs of going to another node
self.prob_sum += prob # until 100%
if self.random_num < self.prob_sum: # passed percentile, go to another node
exclude_names = self.names[:i] + self.names[i + 1:] # big list without this node
self.start = exclude_names[ind] # for next iteration
break # found percentile in probs
return self.pos # add current pos to chain
chain = Chain({"A": [50, 25], "B": [50, 25], "C": [50, 50]}, "A")
chain_iter = iter(chain)
for k in range(100):
print(next(chain_iter), end=" ")
輸出（包裝）
A B A A B B C B A B A C A B C B A C B A B C B B C
B A B C B A C A B A A B C B B A B B A B A C B C B
B C A B A C A C B A C A B A B A C A B B C B A B A
C A C A C B A A C B A A B B B A A A C A A B A B B
添加回答
舉報
0/150
提交
取消