Ich habe mir selbst eine Tensorflow-Klasse geschrieben wie unten, aber ich habe ein Problem, wenn ich versuche, etwas Gewicht auf Null nach dem Training manuell in der Funktion refine_init_weight
einzustellen. In dieser Funktion habe ich versucht, alle Zahlen auf Null zu setzen, sobald sie unter einem bestimmten Wert liegen, und sehe, wie sich die Genauigkeitsrate ändern würde. Das Problem ist, wenn ich reran self.sess.run(self.accuracy, feed_dict={self.var_X: self.X_test, self.var_Y: self.y_test})
, es scheint, dass sein Wert nicht entsprechend geändert wird. Ich frage mich nur, wo sollte ich die symbolische Variable (die Genauigkeit hängt von den Gewichten, die ich geändert habe) in diesem Fall ändern?Wie ändere ich die symbolische Variable (tf.Variable) im Tensorflow?
import tensorflow as tf
from nncomponents import *
from helpers import *
from sda import StackedDenoisingAutoencoder
class DeepFeatureSelection:
def __init__(self, X_train, X_test, y_train, y_test, weight_init='sda', hidden_dims=[100, 100, 100], epochs=1000,
lambda1=0.001, lambda2=1.0, alpha1=0.001, alpha2=0.0, learning_rate=0.1, optimizer='FTRL'):
# Initiate the input layer
# Get the dimension of the input X
n_sample, n_feat = X_train.shape
n_classes = len(np.unique(y_train))
self.epochs = epochs
# Store up original value
self.X_train = X_train
self.y_train = one_hot(y_train)
self.X_test = X_test
self.y_test = one_hot(y_test)
# Two variables with undetermined length is created
self.var_X = tf.placeholder(dtype=tf.float32, shape=[None, n_feat], name='x')
self.var_Y = tf.placeholder(dtype=tf.float32, shape=[None, n_classes], name='y')
self.input_layer = One2OneInputLayer(self.var_X)
self.hidden_layers = []
layer_input = self.input_layer.output
# Initialize the network weights
weights, biases = init_layer_weight(hidden_dims, X_train, weight_init)
print(type(weights[0]))
# Create hidden layers
for init_w,init_b in zip(weights, biases):
self.hidden_layers.append(DenseLayer(layer_input, init_w, init_b))
layer_input = self.hidden_layers[-1].output
# Final classification layer, variable Y is passed
self.softmax_layer = SoftmaxLayer(self.hidden_layers[-1].output, n_classes, self.var_Y)
n_hidden = len(hidden_dims)
# regularization terms on coefficients of input layer
self.L1_input = tf.reduce_sum(tf.abs(self.input_layer.w))
self.L2_input = tf.nn.l2_loss(self.input_layer.w)
# regularization terms on weights of hidden layers
L1s = []
L2_sqrs = []
for i in xrange(n_hidden):
L1s.append(tf.reduce_sum(tf.abs(self.hidden_layers[i].w)))
L2_sqrs.append(tf.nn.l2_loss(self.hidden_layers[i].w))
L1s.append(tf.reduce_sum(tf.abs(self.softmax_layer.w)))
L2_sqrs.append(tf.nn.l2_loss(self.softmax_layer.w))
self.L1 = tf.add_n(L1s)
self.L2_sqr = tf.add_n(L2_sqrs)
# Cost with two regularization terms
self.cost = self.softmax_layer.cost \
+ lambda1*(1.0-lambda2)*0.5*self.L2_input + lambda1*lambda2*self.L1_input \
+ alpha1*(1.0-alpha2)*0.5 * self.L2_sqr + alpha1*alpha2*self.L1
# FTRL optimizer is used to produce more zeros
# self.optimizer = tf.train.FtrlOptimizer(learning_rate=learning_rate).minimize(self.cost)
self.optimizer = optimize(self.cost, learning_rate, optimizer)
self.accuracy = self.softmax_layer.accuracy
self.y = self.softmax_layer.y
def train(self, batch_size=100):
sess = tf.Session()
self.sess = sess
sess.run(tf.initialize_all_variables())
for i in xrange(self.epochs):
x_batch, y_batch = get_batch(self.X_train, self.y_train, batch_size)
sess.run(self.optimizer, feed_dict={self.var_X: x_batch, self.var_Y: y_batch})
if i % 2 == 0:
l = sess.run(self.cost, feed_dict={self.var_X: x_batch, self.var_Y: y_batch})
print('epoch {0}: global loss = {1}'.format(i, l))
self.selected_w = sess.run(self.input_layer.w)
print("Train accuracy:",sess.run(self.accuracy, feed_dict={self.var_X: self.X_train, self.var_Y: self.y_train}))
print("Test accuracy:",sess.run(self.accuracy, feed_dict={self.var_X: self.X_test, self.var_Y: self.y_test}))
print(self.selected_w)
print(len(self.selected_w[self.selected_w==0]))
print("Final test accuracy:",sess.run(self.accuracy, feed_dict={self.var_X: self.X_test, self.var_Y: self.y_test}))
def refine_init_weight(self, threshold=0.001):
refined_w = np.copy(self.selected_w)
refined_w[refined_w < threshold] = 0
self.input_layer.w.assign(refined_w)
print("Test accuracy refined:",self.sess.run(self.accuracy, feed_dict={self.var_X: self.X_test, self.var_Y: self.y_test}))
Sie müssen die Operation 'self.input_layer.w.assign (raffinierte_w)' –
Danke Olivier! – xxx222