python - 有条件的 Numpy 均值

我有计算纯python平均速度的算法:

speed = [...]
avg_speed = 0.0
speed_count = 0

for i in speed:
    if i > 0: # I dont need zeros
        avg_speed += i
        speed_count += 1

if speed_count == 0:
    return 0.0

return avg_speed / speed_count

有没有办法用 Numpy 重写这个函数？

最佳答案

import numpy as np

def avg_positive_speed(speed):
    s = np.array(speed)
    positives = s > 0
    if positives.any():
        return s[positives].mean()
    else:
        return 0.


speed = [1., 2., 0., 3.]
print avg_positive_speed(speed)
# prints 2.0

print avg_positive_speed([0., 0.])
# prints 0.0

关于python - 有条件的 Numpy 均值，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/11084710/