Exemplo n.º 1
0
def forward_propagation(X, parameters):
    '''
    '''
    # 初始化参数的值
    W1 = parameters['W1']
    b1 = parameters['b1']

    W2 = parameters['W2']
    b2 = parameters['b2']

    W3 = parameters['W3']
    b3 = parameters['b3']

    # 正向传播
    Z1 = np.dot(W1, X) + b1
    A1 = AF.relu(Z1)

    Z2 = np.dot(W2, A1) + b2
    A2 = AF.relu(Z2)

    Z3 = np.dot(W3, A2) + b3
    A3 = AF.sigimoid(Z3)

    cache = (A1, Z1, W1, b1, A2, Z2, W2, b2, A3, Z3, W3, b3)

    return A3, cache
def linear_activation_forward(A_prev, W, b, activation):
    """
    Implement the forward propagation for the LINEAR->ACTIVATION layer

    Arguments:
    A_prev -- activations from previous layer (or input data): (size of previous layer, number of examples)
    W -- weights matrix: numpy array of shape (size of current layer, size of previous layer)
    b -- bias vector, numpy array of shape (size of the current layer, 1)
    activation -- the activation to be used in this layer, stored as a text string: "sigmoid" or "relu"

    Returns:
    A -- the output of the activation function, also called the post-activation value 
    cache -- a python tuple containing "linear_cache" and "activation_cache";
             stored for computing the backward pass efficiently
    """

    if (activation == 'relu'):
        Z, linear_cache = linear_forward(A_prev, W, b)
        A, activation_cache = relu(Z)

    elif (activation == 'sigmoid'):
        Z, linear_cache = linear_forward(A_prev, W, b)
        A, activation_cache = sigmoid(Z)

    cache = (linear_cache, activation_cache)

    return A, cache
Exemplo n.º 3
0
 def convolution_layer0(self):
     for i in range(len(self.conv0_filter)):
         feature_map = np.zeros([self.input.shape[0] - 2,self.input.shape[1] - 2])
         for y in range(feature_map.shape[0]):
             for x in range(feature_map.shape[1]):
                 sum = np.sum(self.input[y:y + 3,x:x + 3] * self.conv0_filter[i])
                 feature_map[y][x] = af.relu(sum + self.conv0_bweight[i])
         self.conv0_feature_map.append(feature_map)
 def predict(self, X):
     lin = linear()
     act = relu()
     classifier = softmax()
     A = X
     for l in range(len(self.layer_dims) - 1):
         Z = lin.forward(A, self.W[l], self.b[l])
         A = act.forward(Z)
     Y_het = classifier.forward(A)
     return Y_het
Exemplo n.º 5
0
 def convolution_layer1(self):
     for i in range(len(self.conv1_filter)):
         v = []
         for j in range(len(self.conv1_filter[i])):
             v.append(np.zeros([self.pool0_out[j].shape[0] - 2,self.pool0_out[j].shape[1] - 2]))
             for y in range(v[j].shape[0]):
                 for x in range(v[j].shape[1]):
                     v[j][y][x] = np.sum(self.pool0_out[j][y:y+3,x:x+3] * self.conv1_filter[i][j])
         feature_map = af.relu(sum(v) + self.conv1_bweight[i])
         self.conv1_feature_map.append(feature_map)
Exemplo n.º 6
0
def forward_propagation_dropout(X, parameters, keep_prob=0.5):
    '''
    加入了dropout的向前传播,输出层不加dropout
    '''
    # 初始化参数的值
    np.random.seed(1)
    W1 = parameters['W1']
    b1 = parameters['b1']

    W2 = parameters['W2']
    b2 = parameters['b2']

    W3 = parameters['W3']
    b3 = parameters['b3']

    # 正向传播
    Z1 = np.dot(W1, X) + b1
    A1 = AF.relu(Z1)
    # 加入dropout
    D1 = np.random.rand(A1.shape[0], A1.shape[1])  #step1 初始换一个和A1相同维数的矩阵
    D1 = D1 < keep_prob  #step2 将D1的值转换为0或1
    A1 = A1 * D1  #step3 舍弃A1中的一些节点, 将其激活值变为0
    A1 = A1 / keep_prob  #step4 缩放未舍弃的节点的值

    Z2 = np.dot(W2, A1) + b2
    A2 = AF.relu(Z2)
    # 加入dropout
    D2 = np.random.rand(A2.shape[0], A2.shape[1])  #step1 初始换一个和A2相同维数的矩阵
    D2 = D2 < keep_prob  #step2 将D2的值转换为0或1
    A2 = A2 * D2  #step3 舍弃A2中的一些节点, 将其激活值变为0
    A2 = A2 / keep_prob  #step4 缩放未舍弃的节点的值

    Z3 = np.dot(W3, A2) + b3
    A3 = AF.sigimoid(Z3)

    cache = (A1, D1, Z1, W1, b1, A2, D2, Z2, W2, b2, A3, Z3, W3, b3)

    return A3, cache
Exemplo n.º 7
0
    print("---------------------------------------------")
    print("Unique fruits:           ", len(paths))
    print("Total fruits:            ", tot_data)
    print("Image resolution:         %ix%i" % (im_shape, im_shape))
    print("Max data set to:         ", max_data)
    print("Total runs:              ", 20)
    print("Total fruit per run:     ", lim_data)
    print("---------------------------------------------")

    ce = CE()
    acc_score = accuracy()
    scaler = StandardScaler()

    if color_scale:
        layer1 = DenseLayer(im_shape * im_shape, 3000, relu(), Glorot=True)
    else:
        layer1 = DenseLayer(im_shape * im_shape * 3, 3000, relu(), Glorot=True)
    layer2 = DenseLayer(3000, 1000, relu(), Glorot=True)
    layer3 = DenseLayer(1000, 200, relu(), Glorot=True)
    layer4 = DenseLayer(200, 10, relu(), Glorot=True)
    layer5 = DenseLayer(10, num_fruits, softmax())

    layers = [layer1, layer2, layer3, layer4, layer5]
    network = NN(layers, ce)

    for i in trange(20):
        print("Run:   ", i + 1)
        data = extract_data(paths,
                            true_labels,
                            lim_data=lim_data,
 def train(self,
           X,
           Y,
           iteration,
           learning_rate,
           lambd=0,
           keep_prob=1,
           interrupt_threshold=0.1,
           print_loss=True):
     # import function
     init = initialization(self.layer_dims)
     lin = linear()
     act = relu()
     drop = dropout(keep_prob)
     classifier = softmax()
     regulator = l2(lambd)
     optimizer = adam(learning_rate)
     # initialization
     counter = 0
     train_X, validation_X, train_Y, validation_Y = train_test_split(
         X, Y, test_size=0.2, shuffle=True)
     self.W, self.b = init.he()
     # iteration
     for i in range(iteration):
         m = Y.shape[0]
         # forward
         A = train_X
         cache = [[None, A, None]]
         for l in range(len(self.layer_dims) - 1):
             Z = lin.forward(A, self.W[l], self.b[l])
             A = act.forward(Z)
             A, D = drop.forward(A)
             cache.append([Z, A, D])
         # loss
         prob = classifier.forward(A)
         loss_tmp1 = classifier.loss(train_Y, prob)
         loss_tmp2 = regulator.loss(self.W, m)
         loss_tmp = loss_tmp1 + loss_tmp2
         self.loss.append(loss_tmp)
         # validation accuracy
         pred = self.predict(validation_X)
         pred = one_hot_vector.decoder(pred)
         acc_tmp = np.mean(validation_Y == pred)
         self.accuracy.append(acc_tmp)
         # print
         if print_loss and i % 1000 == 0:
             print("Iteration %i, Loss: %f, Accuracy: %.f%%" %
                   (i, loss_tmp, acc_tmp * 100))
         if loss_tmp <= interrupt_threshold:
             print("Iteration %i, Loss: %f <= Threshold: %f" %
                   (i, loss_tmp, interrupt_threshold))
             return
         # backward
         dA = classifier.backward(train_Y, prob)
         for l in range(len(self.layer_dims) - 1, 1, -1):
             dA = drop.backward(dA, cache[l][2])
             dZ = act.backward(dA, cache[l][0])
             dA, dW, db = lin.backward(dZ, cache[l - 1][1], self.W[l - 1],
                                       self.b[l - 1], m)
             dW += regulator.backward(self.W[l - 1], m)
             # update
             counter += 1
             self.W[l - 1], self.b[l - 1] = optimizer.update(
                 [self.W[l - 1], self.b[l - 1]], [dW, db], counter)
 def test_relu(self):
     self.assertEqual(af.relu(-1), 0)
     self.assertEqual(af.relu(0), 0)
     self.assertEqual(af.relu(1), 1)
     self.assertEqual(af.relu(5), 5)
Exemplo n.º 10
0
        heatmap.set_xlabel(r"$\eta$")
        heatmap.set_ylabel(r"$\lambda$")
        heatmap.invert_yaxis()
        heatmap.set_title("MSE on Franke dataset with Keras")
        fig = heatmap.get_figure()
        plt.show()
        fig.savefig("../figures/Franke_Keras.pdf",
                    bbox_inches='tight',
                    pad_inches=0.1)

    if franke_relu == True:
        MSE_relu = np.zeros(
            (len(etas), len(epochs)))  # 2 so we can use plot_acc.py
        for i, eta in enumerate(etas):
            #Setting up network
            layer1 = DenseLayer(2, n_neurons_layer1, relu())
            layer2 = DenseLayer(n_neurons_layer1, n_neurons_layer2, relu())
            layer3 = DenseLayer(n_neurons_layer2, 1, identity())
            layers = [layer1, layer2, layer3]
            network = NN(layers)
            k = 0
            for j in range(epochs[-1] + 1):
                random.shuffle(ind)
                x_train_shuffle = x_train[ind]
                y_train_shuffle = y_train[ind]
                network.SGD(mse,
                            100,
                            x_train_shuffle,
                            y_train_shuffle,
                            eta,
                            penalty=0)