import numpy as np

import time

v0=np.loadtxt('V0.txt')

w0=np.loadtxt('W0.txt')

X=np.loadtxt('nnmf-2429-by-361-face.txt')

def NNMF(X,r,tol,V=v0,W=w0,verbose=1):

V = v0[:,0:r]

W = w0[0:r,:]

#Frobinius norm at previous step

B = np.dot(V,W)

L = np.linalg.norm(X-B)**2

iteration = 0

while 1:

#update V

V *= np.dot(X,W.T)

V /= np.dot(B,W.T)

B = np.dot(V,W)

#update W

W *= np.dot(V.T,X)

W /= np.dot(V.T,B)

B = np.dot(V,W)

Lnew = np.linalg.norm(X-B)**2

if abs(Lnew-L) <= tol*(L+1):

break

else:

L = Lnew

iteration += 1

if(verbose and iteration%50==0):

print "At iteration %i, the loss is %.2f" %(iteration, L)

return V,W,iteration

for i in range(5):

r = i*10+10

start = time.time()

V,W,iteration = NNMF(X,r,1e-4,verbose=0)

end = time.time()

print "Elapsed time for Rank-%i model is %.2f seconds" %(r,end-start)