Why doesn't the formula work?

Question

Python

There is such a formula:

Using this formula, I try to calculate my values ​​using the numpy library:
I got the following code:

N = np.arange(proc+1)
np.sum(np.power(R, N) / (math.factorial(N)))

I end up with the following error:

TypeError: only size-1 arrays can be converted to Python scalars

Does anyone know how to solve this error?

Answer 1

To apply factorial to arrays, you need to vectorize the function:

>>> import numpy as np
>>> np.math.factorial(np.arange(6))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: only size-1 arrays can be converted to Python scalars

>>> factorial = np.vectorize(np.math.factorial)
>>> factorial(np.arange(6))
array([  1,   1,   2,   6,  24, 120])