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a301b73 Sep 22, 2017
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@hunkim @dextto @skyer9
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# Lab 7 Learning rate and Evaluation
import tensorflow as tf
import random
import matplotlib.pyplot as plt
tf.set_random_seed(777) # for reproducibility
from tensorflow.examples.tutorials.mnist import input_data
# Check out https://www.tensorflow.org/get_started/mnist/beginners for
# more information about the mnist dataset
mnist = input_data.read_data_sets("MNIST_data/", one_hot=True)
nb_classes = 10
# MNIST data image of shape 28 * 28 = 784
X = tf.placeholder(tf.float32, [None, 784])
# 0 - 9 digits recognition = 10 classes
Y = tf.placeholder(tf.float32, [None, nb_classes])
W = tf.Variable(tf.random_normal([784, nb_classes]))
b = tf.Variable(tf.random_normal([nb_classes]))
# Hypothesis (using softmax)
hypothesis = tf.nn.softmax(tf.matmul(X, W) + b)
cost = tf.reduce_mean(-tf.reduce_sum(Y * tf.log(hypothesis), axis=1))
optimizer = tf.train.GradientDescentOptimizer(learning_rate=0.1).minimize(cost)
# Test model
is_correct = tf.equal(tf.arg_max(hypothesis, 1), tf.arg_max(Y, 1))
# Calculate accuracy
accuracy = tf.reduce_mean(tf.cast(is_correct, tf.float32))
# parameters
training_epochs = 15
batch_size = 100
with tf.Session() as sess:
# Initialize TensorFlow variables
sess.run(tf.global_variables_initializer())
# Training cycle
for epoch in range(training_epochs):
avg_cost = 0
total_batch = int(mnist.train.num_examples / batch_size)
for i in range(total_batch):
batch_xs, batch_ys = mnist.train.next_batch(batch_size)
c, _ = sess.run([cost, optimizer], feed_dict={
X: batch_xs, Y: batch_ys})
avg_cost += c / total_batch
print('Epoch:', '%04d' % (epoch + 1),
'cost =', '{:.9f}'.format(avg_cost))
print("Learning finished")
# Test the model using test sets
print("Accuracy: ", accuracy.eval(session=sess, feed_dict={
X: mnist.test.images, Y: mnist.test.labels}))
# Get one and predict
r = random.randint(0, mnist.test.num_examples - 1)
print("Label: ", sess.run(tf.argmax(mnist.test.labels[r:r + 1], 1)))
print("Prediction: ", sess.run(
tf.argmax(hypothesis, 1), feed_dict={X: mnist.test.images[r:r + 1]}))
plt.imshow(
mnist.test.images[r:r + 1].reshape(28, 28),
cmap='Greys',
interpolation='nearest')
plt.show()
'''
Epoch: 0001 cost = 2.868104637
Epoch: 0002 cost = 1.134684615
Epoch: 0003 cost = 0.908220728
Epoch: 0004 cost = 0.794199896
Epoch: 0005 cost = 0.721815854
Epoch: 0006 cost = 0.670184430
Epoch: 0007 cost = 0.630576546
Epoch: 0008 cost = 0.598888191
Epoch: 0009 cost = 0.573027079
Epoch: 0010 cost = 0.550497213
Epoch: 0011 cost = 0.532001859
Epoch: 0012 cost = 0.515517795
Epoch: 0013 cost = 0.501175288
Epoch: 0014 cost = 0.488425370
Epoch: 0015 cost = 0.476968593
Learning finished
Accuracy: 0.888
'''