Python Multiprocessing Of A Sum

I dont get my code to run, and as others, i have problems in understand how multiprocessing works. here is my code so far if __name__ == '__main__': start = time.clock() bi

Solution 1:

This solution works and I am using the vectorized solution proposed here in order to avoid the Python loops:

from multiprocessing import Pool

import numpy as np

def calc(t_full, w, dataCOS):
    thetas = np.multiply.outer((2*np.pi*t_full), w)
    thetas += 2*np.pi*np.random.random(thetas.shape)

    signal = np.cos(thetas)
    signal *= dataCOS

    signal = signal.sum(-1)

    return signal

def parallel_calc(w, dataCOS, t_full, processes, num):
    '''Parallel calculation

    processes : integer
        Number of processes, usually one processor for each process
    num : integer
        Number of sub-divisions for `w` and `dataCOS`
        Must be an exact divisor of `len(w)` and `len(dataCOS)`
    '''
    pool = Pool(processes=processes)
    #
    results = []
    wd = np.vstack((w, dataCOS))
    for wd_s in np.split(wd.T, num):
        w_s = wd_s.T[0]
        d_s = wd_s.T[1]
        results.append(pool.apply_async(calc, (t_full, w_s, d_s)))
    #
    pool.close()
    pool.join()
    return sum((r.get() for r in results))

if __name__ == '__main__':
    w = np.random.random(1000)
    dataCOS = np.random.random(1000)
    t_full = np.arange(2**16)
    #
    parallel_calc(w, dataCOS, t_full, 4, 10)