def main():
optimizer = Adam()
#-----
# MLP
#-----
data = datasets.load_digits()
X = data.data
y = data.target
# Convert to one-hot encoding
y = to_categorical(y.astype("int"))
n_samples, n_features = X.shape
n_hidden = 512
X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.4, seed=1)
clf = NeuralNetwork(optimizer=optimizer,
loss=CrossEntropy,
validation_data=(X_test, y_test))
clf.add(Dense(n_hidden, input_shape=(n_features,)))
clf.add(Activation('leaky_relu'))
clf.add(Dense(n_hidden))
clf.add(Activation('leaky_relu'))
clf.add(Dropout(0.25))
clf.add(Dense(n_hidden))
clf.add(Activation('leaky_relu'))
clf.add(Dropout(0.25))
clf.add(Dense(n_hidden))
clf.add(Activation('leaky_relu'))
clf.add(Dropout(0.25))
clf.add(Dense(10))
clf.add(Activation('softmax'))
print ()
clf.summary(name="MLP")
train_err, val_err = clf.fit(X_train, y_train, n_epochs=50, batch_size=256)
# Training and validation error plot
n = len(train_err)
training, = plt.plot(range(n), train_err, label="Training Error")
validation, = plt.plot(range(n), val_err, label="Validation Error")
plt.legend(handles=[training, validation])
plt.title("Error Plot")
plt.ylabel('Error')
plt.xlabel('Iterations')
plt.show()
_, accuracy = clf.test_on_batch(X_test, y_test)
print ("Accuracy:", accuracy)
# Reduce dimension to 2D using PCA and plot the results
y_pred = np.argmax(clf.predict(X_test), axis=1)
Plot().plot_in_2d(X_test, y_pred, title="Multilayer Perceptron", accuracy=accuracy, legend_labels=range(10))
def main():
# define the model
components = 3
optimizer = Adam()
loss = MdnLoss(num_components=components, output_dim=1)
clf = NeuralNetwork(optimizer=optimizer, loss=loss)
clf.add(Dense(n_units=26, input_shape=(1, )))
clf.add(Activation('tanh'))
clf.add(
MDN(input_shape=(26, ), output_shape=(1, ), num_components=components))
clf.summary(name="MDN")
# generate 1D regression data (Bishop book, page 273).
# Note: P(y|x) is not a nice distribution.
# (e.g.) it has three modes for x ~= 0.5
N = 225
X = np.linspace(0, 1, N)
Y = X + 0.3 * np.sin(2 * 3.1415926 * X) + np.random.uniform(-0.1, 0.1, N)
X, Y = Y, X
nb = N # full_batch
xbatch = np.reshape(X[:nb], (nb, 1))
ybatch = np.reshape(Y[:nb], (nb, 1))
train_err, val_err = clf.fit(xbatch,
ybatch,
n_epochs=int(4e3),
batch_size=N)
plt.plot(train_err, label="Training Error")
plt.title("Error Plot")
plt.ylabel('Error')
plt.xlabel('Iterations')
plt.show()
# utility function for creating contour plot of the predictions
n = 15
xx = np.linspace(0, 1, n)
yy = np.linspace(0, 1, n)
xm, ym = np.meshgrid(xx, yy)
loss, acc = clf.test_on_batch(xm.reshape(xm.size, 1),
ym.reshape(ym.size, 1))
ypred = clf.loss_function.ypred
plt.figure(figsize=(10, 10))
plt.scatter(X, Y, color='g')
plt.contour(xm,
ym,
np.reshape(ypred, (n, n)),
levels=np.linspace(ypred.min(), ypred.max(), 20))
plt.xlabel('x')
plt.ylabel('y')
plt.title('{}-component Gaussian Mixture Model for '
'P(y|x)'.format(components))
plt.show()
def main():
#----------
# Conv Net
#----------
optimizer = Adam()
data = datasets.load_digits()
X = data.data
y = data.target
# Convert to one-hot encoding
y = to_categorical(y.astype("int"))
X_train, X_test, y_train, y_test = train_test_split(X,
y,
test_size=0.4,
seed=1)
# Reshape X to (n_samples, channels, height, width)
X_train = X_train.reshape((-1, 1, 8, 8))
X_test = X_test.reshape((-1, 1, 8, 8))
clf = NeuralNetwork(optimizer=optimizer,
loss=CrossEntropy,
validation_data=(X_test, y_test))
clf.add(
Conv2D(n_filters=16,
filter_shape=(3, 3),
stride=1,
input_shape=(1, 8, 8),
padding='same'))
clf.add(Activation('relu'))
clf.add(Dropout(0.25))
clf.add(BatchNormalization())
clf.add(Conv2D(n_filters=32, filter_shape=(3, 3), stride=1,
padding='same'))
clf.add(Activation('relu'))
clf.add(Dropout(0.25))
clf.add(BatchNormalization())
clf.add(Flatten())
clf.add(Dense(256))
clf.add(Activation('relu'))
clf.add(Dropout(0.4))
clf.add(BatchNormalization())
clf.add(Dense(10))
clf.add(Activation('softmax'))
print()
clf.summary(name="ConvNet")
train_err, val_err = clf.fit(X_train, y_train, n_epochs=50, batch_size=256)
# Training and validation error plot
n = len(train_err)
training, = plt.plot(range(n), train_err, label="Training Error")
validation, = plt.plot(range(n), val_err, label="Validation Error")
plt.legend(handles=[training, validation])
plt.title("Error Plot")
plt.ylabel('Error')
plt.xlabel('Iterations')
plt.show()
_, accuracy = clf.test_on_batch(X_test, y_test)
print("Accuracy:", accuracy)
y_pred = np.argmax(clf.predict(X_test), axis=1)
X_test = X_test.reshape(-1, 8 * 8)
# Reduce dimension to 2D using PCA and plot the results
Plot().plot_in_2d(X_test,
y_pred,
title="Convolutional Neural Network",
accuracy=accuracy,
legend_labels=range(10))
def main():
#----------
# Conv Net
#----------
optimizer = Adam()
data = datasets.load_digits()
X = data.data
y = data.target
# Convert to one-hot encoding
y = to_categorical(y.astype("int"))
n_samples = np.shape(X)
n_hidden = 512
X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.4, seed=1)
# Reshape X to (n_samples, channels, height, width)
X_train = X_train.reshape((-1,1,8,8))
X_test = X_test.reshape((-1,1,8,8))
clf = NeuralNetwork(optimizer=optimizer,
loss=CrossEntropy,
validation_data=(X_test, y_test))
clf.add(Conv2D(n_filters=16, filter_shape=(3,3), input_shape=(1,8,8), padding='same'))
clf.add(Activation('relu'))
clf.add(Dropout(0.25))
clf.add(BatchNormalization())
clf.add(Conv2D(n_filters=32, filter_shape=(3,3), padding='same'))
clf.add(Activation('relu'))
clf.add(Dropout(0.25))
clf.add(BatchNormalization())
clf.add(Flatten())
clf.add(Dense(256))
clf.add(Activation('relu'))
clf.add(Dropout(0.4))
clf.add(BatchNormalization())
clf.add(Dense(10))
clf.add(Activation('softmax'))
print ()
clf.summary(name="ConvNet")
train_err, val_err = clf.fit(X_train, y_train, n_epochs=50, batch_size=256)
# Training and validation error plot
n = len(train_err)
training, = plt.plot(range(n), train_err, label="Training Error")
validation, = plt.plot(range(n), val_err, label="Validation Error")
plt.legend(handles=[training, validation])
plt.title("Error Plot")
plt.ylabel('Error')
plt.xlabel('Iterations')
plt.show()
_, accuracy = clf.test_on_batch(X_test, y_test)
print ("Accuracy:", accuracy)
y_pred = np.argmax(clf.predict(X_test), axis=1)
X_test = X_test.reshape(-1, 8*8)
# Reduce dimension to 2D using PCA and plot the results
Plot().plot_in_2d(X_test, y_pred, title="Convolutional Neural Network", accuracy=accuracy, legend_labels=range(10))