import numpy as np
%matplotlib inline
import matplotlib.pyplot as plt
import seaborn as sns

"""
Explanation: Numpy Exercise 2
Imports
End of explanation
"""


def np_fact(n):
#     if n == 0:
#         return 1
#     elif n == 1:
#         return 1
#     elif n == 10:
#         return 3628800

    if n==0: 
        return 1
    return np.cumprod(np.arange(1.0,n+1.0,1.0))[-1.0]
print np_fact(10)
    

assert np_fact(0)==1
assert np_fact(1)==1
assert np_fact(10)==3628800
assert [np_fact(i) for i in range(0,11)]==[1,1,2,6,24,120,720,5040,40320,362880,3628800]

"""
Explanation: Factorial
Write a function that computes the factorial of small numbers using np.arange and np.cumprod.
End of explanation
"""


def loop_fact(n):
    q = 1
    for i in range(n):
        q = q * (i+1)
    return q

print np_fact(5)

assert loop_fact(0)==1
assert loop_fact(1)==1
assert loop_fact(10)==3628800
assert [loop_fact(i) for i in range(0,11)]==[1,1,2,6,24,120,720,5040,40320,362880,3628800]

"""
Explanation: Write a function that computes the factorial of small numbers using a Python loop.
End of explanation
"""


# YOUR CODE HERE
# raise NotImplementedError()
%timeit -n1 -r1 np_fact(50)
%timeit -n1 -r1 loop_fact(50)

"""
Explanation: Use the %timeit magic to time both versions of this function for an argument of 50. The syntax for %timeit is:
python
%timeit -n1 -r1 function_to_time()
End of explanation
"""


