XOR perseptron

xor.py

import numpy as np

def S(x):
    return 1/(1+np.exp(-x))

win = np.random.randn(2,2)
wout = np.random.randn(2,1)
eta = 0.25

# dummy values used to see if everything is correct manually
# win = [[1,1], [2,2]]
# wout = [[1],[2]]

obj = [[0,0],[1,0],[0,1],[1,1]]
target = [0,1,1,0]

epoch = int(100000)
emajor = ""

for r in range(0,epoch):

    finalError = [0]
    for xy in range(len(target)):
        tar = target[xy]
        fdata = obj[xy]

        fdata = S(np.dot(1,fdata))

        # print(fdata)

        hnw = np.dot(fdata,win)


        hnw = S(np.dot(fdata,win))

        # print(hnw)

        out = np.dot(hnw,wout)


        out = S(out)

        diff = tar-out

        E = 0.5 * np.power(diff,2)

        finalError += E

        delta_out = (out-tar)*(out*(1-out))
        # print(delta_out)
        nindelta_out = delta_out * eta

        wout_change = np.dot(nindelta_out[0], hnw)

        for x in range(len(wout_change)):
            change = wout_change[x]
            wout[x] -= change

        # I think this np.dot is wrong
        # delta_in = np.dot(hnw,(1-hnw)) * np.dot(delta_out[0], wout)

        # so I looped in in the old fashioned way
        delta_in = []
        for x in range(len(hnw)):
            delta_in = np.append(delta_in, hnw[x]*(1-hnw[x])*delta_out[0]*wout[x])

        #eta into delta
        nindelta_in = eta * delta_in


        for x in range(len(nindelta_in)):
            midway = np.dot(nindelta_in[x], fdata)
            for y in range(len(win)):
                win[y][x] -= midway[y]


    emajor += str(finalError[0]) + ",\n"

# save it in a file to plot it up
f = open('xor.csv','w')
f.write(emajor) # python will convert \n to os.linesep
f.close() # you can omit in most cases as the destructor will call it