Numpy arrays 錯誤地具有相同的值？

Question

我有一個小程序，我正在玩創建與疾病傳播相關的進化算法。 我遇到了一個問題，讓我有點瘋狂地試圖找出問題所在。

我有兩個 numpy arrays，“感染”，這是一個數組，其中每個元素都是該個人是否已暴露的二進制表示和“current_infections”，這只是持續感染，應該按天遞增。

例如：

感染 = [0,0,0,1,1]
current_infections = [0,0,0,15,0]

這將代表 5 個人，其中 3 個人患有該病 15 天，而 4 個人患有該病的時間足夠長，以至於他們已經康復並且目前不再患有該病。

infections = []
current_infections = []
responsible_infections = []
spread_rate = 0.1
contagious_period = 20
initial_node_infections = 2
current_network = #this is an array of adjacency matrices for nodes in a network


#initial infections.
def initialize_infections():
  global infections, current_infections, responsible_infections
  responsible_infections = np.zeros(current_network.shape[0])
  infections = np.zeros(current_network.shape[0])
  for each in rd.sample(range(len(current_network)), k=initial_node_infections):
    infections[each] = 1
  current_infections = infections[:]

# runs a day in simulation. 
# returns 1 if there are still ongoing infections at the end of day, 0 if not
def progress_day():
  global current_infections
  print(np.sum(current_infections), np.sum(infections))  #should not be equivalent, yet they are
  for i in range(len(current_infections)):
    if current_infections[i] >= 1 and current_infections[i]<contagious_period:
      current_infections[i]+=1
    elif current_infections[i]>=contagious_period:
      #patient recovered
      current_infections[i] = 0
  for i in range(contacts_per_day):
    for j in range(len(current_infections)):
      if current_infections[j] >= 1:
        spread_infection(current_network[j], j)

  if not np.sum(current_infections):
    return 0
  else:
    return 1




#given infected node it calculates spread of disease to adjacent nodes.
def spread_infection(person, rp):
  global infections, current_infections, responsible_infections
  for x in range(len(person)):
    if person[x] == 1 and infections[x] == 0 and rd.random()<=spread_rate:
      current_infections[x] = 1
      infections[x] = 1
      responsible_infections[rp]+=1 #infections a given person is responsible for.


def main():
  global current_infections, infections
  initialize_infections()
  day = 0
  while day<100:
    if not progress_day():
      break
    day+=1

main()

出於某種原因，對 current_infections 中的元素所做的更改也在感染中對該元素進行了更改，因此它們都在遞增。 我是否對 numpy 做錯了什么，以至於它們在某種程度上是同一個數組？

Answer 1

current_infections = infections[:]使 current_infections 成為感染元素的視圖。 使用current_infections = infections.copy() 。