Beispiel #1
0
def train():
    """Train CIFAR-10 for a number of steps."""
    with tf.Graph().as_default():
        global_step = contrib_framework.get_or_create_global_step()

        # Get images and labels for CIFAR-10.
        images, labels = cifar10.distorted_inputs()

        # Create a compression object using the compression hyperparameters
        compression_obj = cifar10.create_compressor(FLAGS.compression_hparams,
                                                    global_step=global_step)

        # Build a Graph that computes the logits predictions from the
        # inference model.
        logits = cifar10.inference(images, compression_obj)

        # Calculate loss.
        loss = cifar10.loss(logits, labels)

        # Build a Graph that trains the model with one batch of examples and
        # updates the model parameters.
        train_op = cifar10.train(loss, global_step, compression_obj)

        class _LoggerHook(tf.train.SessionRunHook):
            """Logs loss and runtime."""
            def begin(self):
                self._step = -1

            def before_run(self, run_context):
                self._step += 1
                self._start_time = time.time()
                return tf.train.SessionRunArgs(loss)  # Asks for loss value.

            def after_run(self, run_context, run_values):
                duration = time.time() - self._start_time
                loss_value = run_values.results
                if self._step % 10 == 0:
                    num_examples_per_step = 128
                    examples_per_sec = num_examples_per_step / duration
                    sec_per_batch = float(duration)

                    format_str = (
                        '%s: step %d, loss = %.2f (%.1f examples/sec; %.3f '
                        'sec/batch)')
                    print(format_str %
                          (datetime.datetime.now(), self._step, loss_value,
                           examples_per_sec, sec_per_batch))

        with tf.train.MonitoredTrainingSession(
                checkpoint_dir=FLAGS.train_dir,
                hooks=[
                    tf.train.StopAtStepHook(last_step=FLAGS.max_steps),
                    tf.train.NanTensorHook(loss),
                    _LoggerHook()
                ],
                config=tf.ConfigProto(log_device_placement=FLAGS.
                                      log_device_placement)) as mon_sess:
            while not mon_sess.should_stop():
                mon_sess.run(train_op)
def eval_once():
    """Run Eval once."""
    with tf.Graph().as_default() as g:
        with tf.Session() as sess:
            ckpt = tf.train.get_checkpoint_state(FLAGS.checkpoint_dir)
            if not (ckpt and ckpt.model_checkpoint_path):
                print('No checkpoint file found')
                return

            # Get images and labels for CIFAR-10.
            eval_data = FLAGS.eval_data == 'test'
            images, labels = cifar10.inputs(eval_data=eval_data)

            global_step = FLAGS.global_step
            # If invalid global step or none provided, use the last global step
            # recorded in the checkpoint file.
            if not global_step or global_step < 0:
                # Assuming model_checkpoint_path looks something like:
                #   /my-favorite-path/cifar10_train/model.ckpt-0,
                # extract global_step from it.
                global_step = ckpt.model_checkpoint_path.split('/')[-1].split(
                    '-')[-1]

            compression_obj = cifar10.create_compressor(
                FLAGS.compression_hparams, global_step=global_step)

            # Build a Graph that computes the logits predictions from the
            # inference model.
            logits = cifar10.inference(images, compression_obj)

            # Calculate predictions.
            top_k_op = tf.nn.in_top_k(logits, labels, 1)

            # Restore the moving average version of the learned variables for eval.
            variable_averages = tf.train.ExponentialMovingAverage(
                cifar10.MOVING_AVERAGE_DECAY)
            variables_to_restore = variable_averages.variables_to_restore()
            saver = tf.train.Saver(variables_to_restore)

            # Restores from checkpoint
            saver.restore(sess, ckpt.model_checkpoint_path)

            # Build the summary operation based on the TF collection of Summaries.
            summary_op = tf.summary.merge_all()

            summary_writer = tf.summary.FileWriter(FLAGS.eval_dir, g)

            # Start the queue runners.
            coord = tf.train.Coordinator()
            try:
                threads = []
                for qr in tf.get_collection(tf.GraphKeys.QUEUE_RUNNERS):
                    threads.extend(
                        qr.create_threads(sess,
                                          coord=coord,
                                          daemon=True,
                                          start=True))

                num_iter = int(math.ceil(FLAGS.num_examples / 128))
                true_count = 0  # Counts the number of correct predictions.
                total_sample_count = num_iter * 128
                step = 0
                while step < num_iter and not coord.should_stop():
                    predictions = sess.run([top_k_op])
                    true_count += np.sum(predictions)
                    step += 1

                # Compute precision @ 1.
                precision = true_count / total_sample_count
                print('%s: precision @ 1 = %.3f' %
                      (datetime.datetime.now(), precision))

                summary = tf.Summary()
                summary.ParseFromString(sess.run(summary_op))
                summary.value.add(tag='Precision @ 1', simple_value=precision)
                summary_writer.add_summary(summary, global_step)
            except Exception as e:  # pylint: disable=broad-except
                coord.request_stop(e)

            coord.request_stop()
            coord.join(threads, stop_grace_period_secs=10)