logistic_regression.py 1.4 KB

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  1. # Import MINST data
  2. import input_data
  3. mnist = input_data.read_data_sets("/tmp/data/", one_hot=True)
  4. import tensorflow as tf
  5. # Parameters
  6. learning_rate = 0.01
  7. training_epochs = 25
  8. batch_size = 100
  9. display_step = 1
  10. # Create model
  11. x = tf.placeholder("float", [None, 784])
  12. y = tf.placeholder("float", [None,10])
  13. W = tf.Variable(tf.zeros([784,10]))
  14. b = tf.Variable(tf.zeros([10]))
  15. activation = tf.nn.softmax(tf.matmul(x,W) + b) #softmax
  16. cost = -tf.reduce_sum(y*tf.log(activation)) #cross entropy
  17. optimizer = tf.train.GradientDescentOptimizer(learning_rate).minimize(cost)
  18. # Train
  19. init = tf.initialize_all_variables()
  20. with tf.Session() as sess:
  21. sess.run(init)
  22. for epoch in range(training_epochs):
  23. avg_cost = 0.
  24. total_batch = int(mnist.train.num_examples/batch_size)
  25. for i in range(total_batch):
  26. batch_xs, batch_ys = mnist.train.next_batch(batch_size)
  27. sess.run(optimizer, feed_dict={x: batch_xs, y: batch_ys})
  28. avg_cost += sess.run(cost, feed_dict={x: batch_xs, y: batch_ys})/total_batch
  29. if epoch % display_step == 0:
  30. print "Epoch:", '%04d' % (epoch+1), "cost=", "{:.9f}".format(avg_cost)
  31. print "Optimization Finished!"
  32. # Test trained model
  33. correct_prediction = tf.equal(tf.argmax(activation,1), tf.argmax(y,1))
  34. accuracy = tf.reduce_mean(tf.cast(correct_prediction, "float"))
  35. print "Accuracy:", accuracy.eval({x: mnist.test.images, y: mnist.test.labels})