Example #1
0
def matrix_multiply(a, b):
    """Takes two matrices and does a complicated matrix multiply.  Yes that one.
    NOTE: THIS APPEARS TO BE VERY BROKEN
    """
    if len(a.shape) == 1:
        nrows, = a.shape
        a = np.zeros((nrows, 1))

    if len(b.shape) == 1:
        bc, = b.shape
        if bc == a.shape[1]:
            b = np.zeros((bc, 1))
        else:
            b = np.zeros((1, bc))
       
    nrows,ac = a.shape
    bc,ncols = b.shape

    assert ac == bc
    if ispypy():
        n = np.zeros((nrows, ncols))
        for i in xrange(nrows):
            for j in xrange(ncols):
                n[i,j] = np.sum(a[i] * b[:,j])
        return n
    else:
        np.dot(a, b)
Example #2
0
def partial_slda_recalculate_eta_sigma(eta, y, phi):
    """
        Same as slda_recalculate_eta_sigma, but also
          supports partial updates if len(eta) < phi.shape[1] .
          Will only update based on first Ks topics of phi
    """
    D = len(phi)
    ensure(D >= 1)

    N,K = phi[0].shape
    Ks = len(eta)

    print 'e_a...'
    E_A = np.empty((D, Ks))
    for d in xrange(D):
        E_A[d,:] = calculate_EZ(phi[d][:,:Ks])
  
    E_ATA_inverse = calculate_E_ATA_inverse([p[:,:Ks] for p in phi])

    print 'new eta...'
    new_eta = np.dot(np.dot(E_ATA_inverse, E_A.T), y)
    eta[:] = new_eta
    
    print 'new sigma squared...'
    new_sigma_squared = (1.0 / D) * (np.dot(y, y) - np.dot(np.dot(y, E_A), eta))
    return new_sigma_squared
Example #3
0
    def test_dot(self):
        from numpypy import array, dot
        a = array(range(5))
        assert a.dot(a) == 30.0

        a = array(range(5))
        assert a.dot(range(5)) == 30
        assert dot(range(5), range(5)) == 30
        assert (dot(5, [1, 2, 3]) == [5, 10, 15]).all()
Example #4
0
    def test_dot(self):
        from numpypy import array, dot, arange
        a = array(range(5))
        assert dot(a, a) == 30.0

        a = array(range(5))
        assert a.dot(range(5)) == 30
        assert dot(range(5), range(5)) == 30
        assert (dot(5, [1, 2, 3]) == [5, 10, 15]).all()

        a = arange(12).reshape(3, 4)
        b = arange(12).reshape(4, 3)
        c = a.dot(b)
        assert (c == [[ 42, 48, 54], [114, 136, 158], [186, 224, 262]]).all()

        a = arange(24).reshape(2, 3, 4)
        raises(ValueError, "a.dot(a)")
        b = a[0, :, :].T
        #Superfluous shape test makes the intention of the test clearer
        assert a.shape == (2, 3, 4)
        assert b.shape == (4, 3)
        c = dot(a, b)
        assert (c == [[[14, 38, 62], [38, 126, 214], [62, 214, 366]],
                   [[86, 302, 518], [110, 390, 670], [134, 478, 822]]]).all()
        c = dot(a, b[:, 2])
        assert (c == [[62, 214, 366], [518, 670, 822]]).all()
        a = arange(3*2*6).reshape((3,2,6))
        b = arange(3*2*6)[::-1].reshape((2,6,3))
        assert dot(a, b)[2,0,1,2] == 1140
        assert (dot([[1,2],[3,4]],[5,6]) == [17, 39]).all()
Example #5
0
def lm_recalculate_eta_sigma(eta, y, phi1, phi2):
    """
        Accepts eta (K+J)-size vector,
            also y (a D-size vector of reals),
            also two phi D-size vectors of NxK matrices.
        Returns new sigma squared update (a double).

        ηnew ← (E[ATA])-1 E[A]Ty
        σ2new ← (1/D) {yTy - yTE[A]ηnew}

        (Note that A is the D X (K + J) matrix whose rows are the vectors ZdT for document and comment concatenated.)
        (Also note that the dth row of E[A] is φd, and E[ATA] = Σd E[ZdZdT] .)
        (Also, note that E[Z] = φ := (1/N)Σnφn, and E[ZdZdT] = (1/N2)(ΣnΣm!=nφd,nφd,mT  +  Σndiag{φd,n})
    """
    ensure(len(phi1) == len(phi2))
    D = len(phi1)

    Nd,K = phi1[0].shape
    Nc,J = phi2[0].shape
    Ndc, KJ = (Nd+Nc,K+J)

    #print 'e_a...'
    E_A = np.zeros((D, KJ))
    for d in xrange(D):
        E_A[d,:] = calculate_EZ_from_small_phis(phi1[d], phi2[d])
  
    #print 'inverse...'
    E_ATA_inverse = calculate_E_ATA_inverse_from_small_phis(phi1, phi2)

    #print 'new eta...'
    #new_eta = matrix_multiply(matrix_multiply(E_ATA_inverse, E_A.T), y)
    new_eta = np.dot(np.dot(E_ATA_inverse, E_A.T), y)
    if np.sum(np.abs(new_eta)) > (KJ * KJ * 5):
        print 'ETA is GOING CRAZY {0}'.format(eta)
        print 'aborting the update!!!'
    else:
        eta[:] = new_eta
    
    # todo: don't do this later
    # keep sigma squared fix
    #import pdb; pdb.set_trace()
    #new_sigma_squared = (1.0 / D) * (np.dot(y, y) - np.dot(np.dot(np.dot(np.dot(y, E_A), E_ATA_inverse), E_A.T), y))
    new_sigma_squared = 1.0
    return new_sigma_squared
Example #6
0
def partial_slda_update_phi(text, phi, gamma, beta, y_d, eta, sigma_squared):
    """Same as slda update phi, but eta may be smaller than total number of topics.
        So only some of the topics contribute to y.
    """
    (N, K) = phi.shape
    Ks = len(eta)

    phi_sum = np.sum(phi[:,:Ks], axis=0)
    Ns = (N * sigma_squared)
    ElogTheta = graphlib.dirichlet_expectation(gamma)

    front = (-1.0 / (2 * N * Ns))
    eta_dot_eta = front * (eta * eta)
    pC = ((1.0 * y_d / Ns) * eta) + eta_dot_eta

    right_eta_times_const = (front * 2 * eta)

    if isinstance(text, np.ndarray):
        # if text is in array form, do an approximate fast matrix update
        phi_minus_n = -(phi[:,:Ks] - phi_sum)
        phi[:,:] = ElogTheta + np.log(beta[:,text].T)
        phi[:,:Ks] += pC
        phi[:,:Ks] += np.dot(np.matrix(np.dot(phi_minus_n, eta)).T, np.matrix(right_eta_times_const))
        graphlib.log_row_normalize(phi)
        phi[:,:] = np.exp(phi[:,:])
    else:
        # otherwise, iterate through each word
        for n,word,count in iterwords(text):
            phi_sum -= phi[n,:Ks]

            pB = np.log(beta[:,word])
            pD = (np.dot(eta, phi_sum) * right_eta_times_const) 

            # must exponentiate and normalize immediately!
            phi[n,:] = ElogTheta + pB
            phi[n,:] += pC + pD
            phi[n,:] -= graphlib.logsumexp(phi[n,:]) # normalize in logspace
            phi[n,:] = np.exp(phi[n,:])


            # add this back into the sum
            # unlike in LDA, this cannot be computed in parallel
            phi_sum += phi[n,:Ks]
    return phi
Example #7
0
def calculate_EZZT_from_small_phis(phi1, phi2):
    """
        Accepts a big phi matrix (like ((Nd+Nc) x (K+J))
        Calculates E[ZdZdT].
        Returns the final matrix ((K+J) x (K+J)).

        (Also, E[ZdZdT] = (1/N2)(ΣNΣm!=nφd,nφd,mT  +  ΣNdiag{φd,n})
    """
    Nd,K = phi1.shape
    Nc,J = phi2.shape
    (Ndc, KJ) = (Nd+Nc, K+J)
    inner_sum = np.zeros((KJ, KJ))

    p1 = np.matrix(phi1)
    p2 = np.matrix(phi2)

    for i in xrange(K):
        for j in xrange(K):
            m = np.dot(np.matrix(p1[:,i]), np.matrix(p1[:,j]).T)
            inner_sum[i,j] = np.sum(m) - np.sum(np.diagonal(m))

    for i in xrange(J):
        for j in xrange(J):
            m = np.dot(np.matrix(p2[:,i]), np.matrix(p2[:,j]).T)
            inner_sum[K+i,K+j] = np.sum(m) - np.sum(np.diagonal(m))

    for i in xrange(K):
        for j in xrange(J):
            m = np.dot(np.matrix(p1[:,i]), np.matrix(p2[:,j]).T)
            inner_sum[i,K+j] = np.sum(m)

    for i in xrange(J):
        for j in xrange(K):
            m = np.dot(np.matrix(p2[:,i]), np.matrix(p1[:,j]).T)
            inner_sum[K+i,j] = np.sum(m)

    big_phi_sum = np.concatenate((np.sum(phi1, axis=0),
                                  np.sum(phi2, axis=0)), axis=1)
    ensure(big_phi_sum.shape == (KJ,))
    inner_sum += np.diagonal(big_phi_sum)

    inner_sum /= (Ndc * Ndc)
    return inner_sum
Example #8
0
 def test_dot_constant(self):
     from numpypy import array, dot
     a = array(range(5))
     b = a.dot(2.5)
     for i in xrange(5):
         assert b[i] == 2.5 * a[i]
     c = dot(4, 3.0)
     assert c == 12.0
     c = array(3.0).dot(array(4))
     assert c == 12.0
Example #9
0
def lm_elbo_y_from_small_phis(y, eta, phiD, phiC, sigma_squared):
    """
    Calculates some terms in the elbo for a document.
    Same as in sLDA.

    E[log p(y|Z1:N,η,σ2)] = (–1/2)log 2πσ2 – (1/2σ2)[y2– 2yηTE[Z] + ηTE[ZZT]η]

    Test:
    Should be the same as slda_elbo_y when phiD and phiC are catercorner concatenated.
    """
    elbo = 0.0
    ss = sigma_squared
    elbo += (-0.5) * np.log(2 * np.pi * ss)
    
    ez = calculate_EZ_from_small_phis(phiD, phiC)
    ezzt = calculate_EZZT_from_small_phis(phiD, phiC)
    nEZZTn = np.dot(np.dot(eta, ezzt), eta)
    elbo += (-0.5 / ss) * (y*y - (2 * y * np.dot(eta, ez)) + nEZZTn)
    return elbo
Example #10
0
def slda_elbo_y(y, eta, phi, sigma_squared):
    """
    Calculates some terms in the elbo for a document.
    Same as in sLDA.

    E[log p(y|Z1:N,η,σ2)] = (–1/2)log 2πσ2 – (1/2σ2)[y2– 2yηTE[Z] + ηTE[ZZT]η]
    """
    elbo = 0.0
    ss = sigma_squared
    elbo += (-0.5) * np.log(2 * np.pi * ss)
    
    #print 'will calculate ez...'
    ez = calculate_EZ(phi)
    #print 'will calculate ezzt...'
    ezzt = calculate_EZZT(phi)
    #print 'will calculate nEZZTn...'
    nEZZTn = np.dot(np.dot(eta, ezzt), eta)
    #print 'will sum up elbo...'
    elbo += (-0.5 / ss) * (y*y - (2 * y * np.dot(eta, ez)) + nEZZTn)
    return elbo
Example #11
0
 def update(self, input_values, trace=False ):
     # This is a forward operation in the network. This is how we 
     # calculate the network output from a set of input signals.
     
     output = input_values
     if trace: tracelist = [ output ]
     
     for i, weight_layer in enumerate(self.weights):
         # Loop over the network layers and calculate the output
         if i == 0:
             output = np.dot( output, weight_layer[1:,:] ) + weight_layer[0:1,:] # implicit bias
         else:
             output = np.dot( output, weight_layer[1:,:] ) + weight_layer[0:1,:] # implicit bias
         
         output = self.activation_functions[i]( output )
         if trace: tracelist.append( output )
     
     if trace: return tracelist
     
     return output
Example #12
0
 def test_dot_out(self):
     from numpypy import arange, dot
     a = arange(12).reshape(3, 4)
     b = arange(12).reshape(4, 3)
     out = arange(9).reshape(3, 3)
     c = dot(a, b, out=out)
     assert (c == out).all()
     assert (c == [[42, 48, 54], [114, 136, 158], [186, 224, 262]]).all()
     out = arange(9, dtype=float).reshape(3, 3)
     exc = raises(ValueError, dot, a, b, out)
     assert exc.value[0] == ('output array is not acceptable (must have the '
                             'right type, nr dimensions, and be a C-Array)')
Example #13
0
def _unoptimized_slda_update_phi(text, phi, gamma, beta, y_d, eta, sigma_squared):
    """
        Update phi in LDA. 
        phi is N x K matrix.
        gamma is a K-size vector

     update phid:
     φd,n ∝ exp{ E[log θ|γ] + 
                 E[log p(wn|β1:K)] + 
                 (y / Nσ2) η  — 
                 [2(ηTφd,-n)η + (η∘η)] / (2N2σ2) }
     
     Note that E[log p(wn|β1:K)] = log βTwn
    """
    (N, K) = phi.shape
    #assert len(eta) == K
    #assert len(gamma) == K
    #assert beta.shape[0] == K

    phi_sum = np.sum(phi, axis=0)
    Ns = (N * sigma_squared)
    ElogTheta = graphlib.dirichlet_expectation(gamma)
    ensure(len(ElogTheta) == K)

    pC = (1.0 * y_d / Ns * eta)  
    eta_dot_eta = (eta * eta)
    front = (-1.0 / (2 * N * Ns))

    for n,word,count in iterwords(text):
        phi_sum -= phi[n]
        ensure(len(phi_sum) == K)

        pB = np.log(beta[:,word])
        pD = (front * (((2 * np.dot(eta, phi_sum) * eta) + eta_dot_eta))
                            )
        ensure(len(pB) == K)
        ensure(len(pC) == K)
        ensure(len(pD) == K)

        # must exponentiate and sum immediately!
        #phi[n,:] = np.exp(ElogTheta + pB + pC + pD)
        #phi[n,:] /= np.sum(phi[n,:])
        # log normalize before exp for numerical stability
        phi[n,:] = ElogTheta + pB + pC + pD
        phi[n,:] -= graphlib.logsumexp(phi[n,:])
        phi[n,:] = np.exp(phi[n,:])

        # add this back into the sum
        # unlike in LDA, this cannot be computed in parallel
        phi_sum += phi[n]

    return phi
    def update(self, input_values, trace=False):
        # This is a forward operation in the network. This is how we
        # calculate the network output from a set of input signals.

        output = input_values
        if trace: tracelist = [output]

        for i, weight_layer in enumerate(self.weights):
            # Loop over the network layers and calculate the output
            if i == 0:
                output = np.dot(output, weight_layer[1:, :]) + weight_layer[
                    0:1, :]  # implicit bias
            else:
                output = np.dot(output, weight_layer[1:, :]) + weight_layer[
                    0:1, :]  # implicit bias

            output = self.activation_functions[i](output)
            if trace: tracelist.append(output)

        if trace: return tracelist

        return output
Example #15
0
def lm_E_step_for_doc(global_iteration,
                        d, document, comment, 
                        alphaD, alphaC, 
                        betaD, betaC, 
                        gammaD, gammaC, 
                        phiD, phiC, 
                        y, eta, sigma_squared):
    """Given phi and gamma matrices and document of the document.
        Recalculate phi and gamma repeatedly iteratively.
        Uses local elbo calculation to check for convergence.
    """
    print "starting E step on doc {0}".format(d)
    graphlib.initialize_random(phiD)
    graphlib.initialize_random(phiC)

    i = 0
    last_local_elbo, local_elbo = graphlib.INITIAL_ELBO - 100, graphlib.INITIAL_ELBO
    while graphlib.elbo_did_not_converge(local_elbo, last_local_elbo, i, 
                                            criterion=0.1, max_iter=20):
        print 'will update gamma...'
        # update gammas
        lda_update_gamma(alphaD, phiD, gammaD)
        lda_update_gamma(alphaC, phiC, gammaC)

        Nd,Kd = phiD.shape

        print 'will update phis...'
        # update phis (note we have to pass the right part of eta!)
        slda_update_phi(document, phiD, gammaD, betaD, y[d], eta[:Kd], sigma_squared)
        slda_update_phi(comment, phiC, gammaC, betaC, y[d], eta[Kd:], sigma_squared)

        print 'will calculate y...'
        # update the response variable
        # y = ηTE[Z] = ηTφ      [  where φ = 1/N * Σnφn   ]
        y[d] = np.dot(eta, calculate_EZ_from_small_phis(phiD, phiC))

        if i % 2 == 0:
            print 'will calculate elbo...'
            # calculate new ELBO
            last_local_elbo = local_elbo
            local_elbo = lm_local_elbo(document, comment, alphaD, alphaC, betaD, betaC, gammaD, gammaC, phiD, phiC, y[d], eta, sigma_squared)
        i += 1

        #print {'beta': (betaD, betaC), 'gamma': (gammaD, gammaC), 'phi': (phiD, phiC), 'y': y, 'eta': eta}
        print "{2}: e-step iteration {0} ELBO: {1}".format(i, local_elbo, global_iteration)
    print "{2}: done e-step on doc {3}: {0} iterations ELBO: {1}".format(i, local_elbo, global_iteration, d)
    return i
Example #16
0
def calculate_EZZT(big_phi):
    """
        Accepts a big phi matrix (like (N x K)
        Calculates E[ZdZdT].
        Returns the final matrix (K x K).

        (Also, E[ZdZdT] = (1/N2)(ΣNΣm!=nφd,nφd,mT  +  ΣNdiag{φd,n})
    """
    (N, K) = big_phi.shape
    inner_sum = np.empty((K, K))

    for i in xrange(K):
        for j in xrange(K):
            inner_sum[i,j] = np.sum(np.multiply.outer(big_phi[:,i], big_phi[:,j])) - np.sum(np.dot(big_phi[:,i], big_phi[:,j]))
    inner_sum += np.diag(np.sum(big_phi, axis=0))
    inner_sum /= (N * N)
    return inner_sum
	def __run(score_task_knapsack, m_tasks, tasks, mac):	

		n = len(tasks)

		Tu = []
		Td = range(0, n)
		Pu = numpy.zeros(2, float)
		Z  = 0
		X  = numpy.zeros(n, int)
		Tc = []
		B  = numpy.ones(2, float)

		P  = numpy.zeros((n, 2), float)
		G  = numpy.zeros(n, float)

		U  = numpy.zeros(n, float)

		for x in range(0, n):
			P[x][0] = m_tasks[tasks[x]].CPU_usage / mac.free_CPU()
			P[x][1] = m_tasks[tasks[x]].mem_usage / mac.free_mem()

		keep_going = True

		cnt = math.sqrt(2)
		#w_cpu = 0.6
		#w_mem = 1 - w_cpu

		#print "MAC = %d, ntasks = %d" % (mac.machine_ID, n)

		while keep_going :
	
			# step 2
			del Tc
			Tc = []
			
			for i in Td:
				if P[i][0] <= (1. - Pu[0]) and P[i][1] <= (1. - Pu[1]):
					Tc.append(i)

			#print "2"

			# step 3
			# terminate if Tc = empty
			if len(Tc) == 0:
				keep_going = False
			else:

				# step 4
				# (a)
				if (numpy.dot(Pu, Pu) == 0.):
					for i in Tc:
						d    = sum(P[i])
						G[i] = (score_task_knapsack(m_tasks[tasks[i]], mac) * cnt)/d
				# (b)
				else:
					mod_Pu = math.sqrt(numpy.dot(Pu, Pu))
					E      = numpy.array(Pu * (1./mod_Pu))
				
					for i in Tc:
						d    = numpy.dot(P[i], E)
						G[i] = score_task_knapsack(m_tasks[tasks[i]], mac) / d

				#print "4"

				# step 5
				v_max = -1
				i_max = 0
				for i in Tc:
					if G[i] > v_max:
						v_max = G[i]
						i_max = i


				#print "5"
				# step 6
				Tu.append(i_max)
				Td.remove(i_max)
				Pu = Pu + P[i_max]
				Z  = Z + m_tasks[tasks[i_max]].CPU_usage


		#print "(%f, %f)" % (mac.capacity_CPU, mac.capacity_memory)
		#print Pu

		return Tu
Example #18
0
 def backpropagation(self, trainingset, ERROR_LIMIT = 1e-3, learning_rate = 0.3, momentum_factor = 0.9  ):
     
     assert trainingset[0].features.shape[0] == self.n_inputs, \
             "ERROR: input size varies from the defined input setting"
     
     assert trainingset[0].targets.shape[0]  == self.n_outputs, \
             "ERROR: output size varies from the defined output setting"
     
     
     training_data    = np.array( [instance.features for instance in trainingset ] )
     training_targets = np.array( [instance.targets for instance in trainingset ] )
     
     MSE              = ( ) # inf
     neterror         = None
     momentum         = collections.defaultdict( int )
     
     batch_size       = self.batch_size if self.batch_size != 0 else training_data.shape[0]
     
     epoch = 0
     while MSE > ERROR_LIMIT:
         epoch += 1
         
         for start in xrange( 0, len(training_data), batch_size ):
             batch             = training_data[start : start+batch_size]
             input_layers      = self.update( training_data, trace=True )
             out               = input_layers[-1]
                           
             error             = out - training_targets
             delta             = error
             MSE               = np.mean( np.power(error,2) )
         
         
             loop  = itertools.izip(
                             xrange(len(self.weights)-1, -1, -1),
                             reversed(self.weights),
                             reversed(input_layers[:-1]),
                         )
         
             for i, weight_layer, input_signals in loop:
                 # Loop over the weight layers in reversed order to calculate the deltas
             
                 if i == 0:
                     dropped = dropout( add_bias(input_signals).T, self.input_layer_dropout  )
                 else:
                     dropped = dropout( add_bias(input_signals).T, self.hidden_layer_dropout )
             
                 # Calculate weight change
                 dW = learning_rate * np.dot( dropped, delta ) + momentum_factor * momentum[i]
             
                 if i!= 0:
                     """Do not calculate the delta unnecessarily."""
                     # Skipping the bias weight during calculation.
                     weight_delta = np.dot( delta, weight_layer[1:,:].T )
         
                     # Calculate the delta for the subsequent layer
                     delta = np.multiply(  weight_delta, self.activation_functions[i-1]( input_signals, derivative=True) )
             
                 # Store the momentum
                 momentum[i] = dW
             
                 # Update the weights
                 self.weights[ i ] -= dW
         
         if epoch%1000==0:
             # Show the current training status
             print "* current network error (MSE):", MSE
     
     print "* Converged to error bound (%.4g) with MSE = %.4g." % ( ERROR_LIMIT, MSE )
     print "* Trained for %d epochs." % epoch
Example #19
0
expectedValueFunction = np.zeros((nGridCapital,nGridProductivity),dtype=float)

# 4. We pre-build output for each point in the grid

for nProductivity in range(nGridProductivity):
    mOutput[:,nProductivity] = vProductivity[nProductivity]*(vGridCapital**aalpha)

## 5. Main iteration

maxDifference = 10.0
tolerance = 0.0000001
iteration = 0

while(maxDifference > tolerance):

    expectedValueFunction = np.dot(mValueFunction,mTransition.T)
        
    for nProductivity in range(nGridProductivity):

        # We start from previous choice (monotonicity of policy function)
        gridCapitalNextPeriod = 0

        for nCapital in range(nGridCapital):

            valueHighSoFar = -100000.0
            capitalChoice  = vGridCapital[0]

            for nCapitalNextPeriod in range(gridCapitalNextPeriod,nGridCapital):

                consumption = mOutput[nCapital,nProductivity] - vGridCapital[nCapitalNextPeriod]
    def backpropagation(self,
                        trainingset,
                        ERROR_LIMIT=1e-3,
                        learning_rate=0.3,
                        momentum_factor=0.9):

        assert trainingset[0].features.shape[0] == self.n_inputs, \
                "ERROR: input size varies from the defined input setting"

        assert trainingset[0].targets.shape[0]  == self.n_outputs, \
                "ERROR: output size varies from the defined output setting"

        training_data = np.array(
            [instance.features for instance in trainingset])
        training_targets = np.array(
            [instance.targets for instance in trainingset])

        MSE = ()  # inf
        neterror = None
        momentum = collections.defaultdict(int)

        batch_size = self.batch_size if self.batch_size != 0 else training_data.shape[
            0]

        epoch = 0
        while MSE > ERROR_LIMIT:
            epoch += 1

            for start in xrange(0, len(training_data), batch_size):
                batch = training_data[start:start + batch_size]
                input_layers = self.update(training_data, trace=True)
                out = input_layers[-1]

                error = out - training_targets
                delta = error
                MSE = np.mean(np.power(error, 2))

                loop = itertools.izip(
                    xrange(len(self.weights) - 1, -1, -1),
                    reversed(self.weights),
                    reversed(input_layers[:-1]),
                )

                for i, weight_layer, input_signals in loop:
                    # Loop over the weight layers in reversed order to calculate the deltas

                    if i == 0:
                        dropped = dropout(
                            add_bias(input_signals).T,
                            self.input_layer_dropout)
                    else:
                        dropped = dropout(
                            add_bias(input_signals).T,
                            self.hidden_layer_dropout)

                    # Calculate weight change
                    dW = learning_rate * np.dot(
                        dropped, delta) + momentum_factor * momentum[i]

                    if i != 0:
                        """Do not calculate the delta unnecessarily."""
                        # Skipping the bias weight during calculation.
                        weight_delta = np.dot(delta, weight_layer[1:, :].T)

                        # Calculate the delta for the subsequent layer
                        delta = np.multiply(
                            weight_delta,
                            self.activation_functions[i - 1](input_signals,
                                                             derivative=True))

                    # Store the momentum
                    momentum[i] = dW

                    # Update the weights
                    self.weights[i] -= dW

            if epoch % 1000 == 0:
                # Show the current training status
                print "* current network error (MSE):", MSE

        print "* Converged to error bound (%.4g) with MSE = %.4g." % (
            ERROR_LIMIT, MSE)
        print "* Trained for %d epochs." % epoch
Example #21
0
 def test_flatiter_array_conv(self):
     from numpypy import array, dot
     a = array([1, 2, 3])
     assert dot(a.flat, a.flat) == 14
Example #22
0
# 4. We pre-build output for each point in the grid

for nProductivity in range(nGridProductivity):
    mOutput[:, nProductivity] = vProductivity[nProductivity] * (vGridCapital**
                                                                aalpha)

## 5. Main iteration

maxDifference = 10.0
tolerance = 0.0000001
iteration = 0

while (maxDifference > tolerance):

    expectedValueFunction = np.dot(mValueFunction, mTransition.T)

    for nProductivity in range(nGridProductivity):

        # We start from previous choice (monotonicity of policy function)
        gridCapitalNextPeriod = 0

        for nCapital in range(nGridCapital):

            valueHighSoFar = -100000.0
            capitalChoice = vGridCapital[0]

            for nCapitalNextPeriod in range(gridCapitalNextPeriod,
                                            nGridCapital):

                consumption = mOutput[