Christopher Flach - 4 months ago 63

Python Question

I'm trying to create a cumulative list, but my output clearly isn't cumulative. Does anyone know what I'm doing wrong?

Thanks

`import numpy as np`

import math

import random

l=[]

for i in range (50):

def nextTime(rateParameter):

return -math.log(1.0 - random.random()) / rateParameter

a = np.round(nextTime(1/15),0)

l.append(a)

np.cumsum(l)

print(l)

Answer

The cumulative sum is not taken *in place*, you have to assign the return value:

```
cum_l = np.cumsum(l)
print(cum_l)
```

You don't need to place that function in the `for`

loop. Putting it outside will avoid defining a new function at every iteration and your code will still produce the expected result.