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import numpy as np

N = 1000000

A = np.random.rand(N)


    

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def mean_plain(A, N):
    sum = 0.0
    j = 0
    while j < N:
        sum += A[j]
        j+=1

    return sum / N


    

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%%timeit -n 1 -r 1

mean_plain(A, N)


    

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%load_ext Cython


    

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%%cython
cimport numpy as np

def mean_cython1(A, N):
    sum = 0.0
    j = 0
    while j < N:
        sum += A[j]
        j+=1

    return sum / N


    

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%%timeit -n 1 -r 1 

mean_cython1(A, N)


    

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%%cython
def mean_cython2(A, int N):
    cdef double sum = 0.0
    cdef int j = 0

    while j < N:
        sum += A[j]  
        j += 1

    return sum / N


    

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%%timeit -n 1 -r 1 

mean_cython2(A, N)


    

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%%cython 
cimport numpy as np

def mean_cython3(np.ndarray[np.float64_t, ndim=1] A, int N):
    cdef double sum = 0.0
    cdef int j = 0

    while j < N:
        sum += A[j]  
        j += 1

    return sum / N


    

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%%timeit -n 1 -r 1

mean_cython3(A, N)


    

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%%cython 
cimport numpy as np
cimport cython

@cython.boundscheck(False)
@cython.wraparound(False)
def mean_cython4(np.ndarray[np.float64_t, ndim=1, mode="c"] A, int N):
    cdef double sum = 0.0
    cdef int j = 0


    while j < N:
        sum += A[j]  
        j += 1

    return sum / N


    

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%%timeit -n 1 -r 1

mean_cython4(A, N)


    

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%%cython 
cimport numpy as np
cimport cython

@cython.boundscheck(False)
@cython.wraparound(False)
def mean_cython5(np.ndarray[np.float64_t, ndim=1, mode="c"] A, int N):
    cdef double sum = 0.0
    cdef int j = 0

    with nogil:
        while j < N:
            sum += A[j]  
            j += 1

    return sum / N


    

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%%timeit -n 1 -r 1

mean_cython5(A, N)