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tensorflowsaverestoreresuming-training

Tensorflow model restoration (resume training seems starting from scratch)


I've a problem for resuming training after saving my model. The problem is that my loss decrease form 6 to 3 for example. At this time I save the model. When I restore it and continue training, the loss restart from 6. It seems that the restoration doesn't really work. I don't understand because printing the weights, it seems that they are loaded properly. I use an ADAM optimizer. Thanks in advance. Here:

    batch_size = self.batch_size 
    num_classes = self.num_classes

    n_hidden = 50 #700 
    n_layers = 1 #3
    truncated_backprop = self.seq_len 
    dropout = 0.3 
    learning_rate = 0.001
    epochs = 200

    with tf.name_scope('input'):
        x = tf.placeholder(tf.float32, [batch_size, truncated_backprop], name='x')
        y = tf.placeholder(tf.int32, [batch_size, truncated_backprop], name='y')

    with tf.name_scope('weights'):
        W = tf.Variable(np.random.rand(n_hidden, num_classes), dtype=tf.float32)
        b = tf.Variable(np.random.rand(1, num_classes), dtype=tf.float32)

    inputs_series = tf.split(x, truncated_backprop, 1)
    labels_series = tf.unstack(y, axis=1)

    with tf.name_scope('LSTM'):
        cell = tf.contrib.rnn.BasicLSTMCell(n_hidden, state_is_tuple=True)
        cell = tf.contrib.rnn.DropoutWrapper(cell, output_keep_prob=dropout)
        cell = tf.contrib.rnn.MultiRNNCell([cell] * n_layers)

    states_series, current_state = tf.contrib.rnn.static_rnn(cell, inputs_series, \
        dtype=tf.float32)

    logits_series = [tf.matmul(state, W) + b for state in states_series]
    prediction_series = [tf.nn.softmax(logits) for logits in logits_series]

    losses = [tf.nn.sparse_softmax_cross_entropy_with_logits(logits=logits, labels=labels) \
        for logits, labels, in zip(logits_series, labels_series)]
    total_loss = tf.reduce_mean(losses)

    train_step = tf.train.AdamOptimizer(learning_rate).minimize(total_loss)

    tf.summary.scalar('total_loss', total_loss)
    summary_op = tf.summary.merge_all()

    loss_list = []
    writer = tf.summary.FileWriter('tf_logs', graph=tf.get_default_graph())

    all_saver = tf.train.Saver()

    with tf.Session() as sess:
        #sess.run(tf.global_variables_initializer())
        tf.reset_default_graph()
        saver = tf.train.import_meta_graph('./models/tf_models/rnn_model.meta')
        saver.restore(sess, './models/tf_models/rnn_model')

        for epoch_idx in range(epochs):
            xx, yy = next(self.get_batch)
            batch_count = len(self.D.chars) // batch_size // truncated_backprop

            for batch_idx in range(batch_count):
                batchX, batchY = next(self.get_batch)

                summ, _total_loss, _train_step, _current_state, _prediction_series = sess.run(\
                    [summary_op, total_loss, train_step, current_state, prediction_series],
                    feed_dict = {
                        x : batchX,
                        y : batchY
                    })

                loss_list.append(_total_loss)
                writer.add_summary(summ, epoch_idx * batch_count + batch_idx)
                if batch_idx % 5 == 0:
                    print('Step', batch_idx, 'Batch_loss', _total_loss)

                if batch_idx % 50 == 0:
                    all_saver.save(sess, 'models/tf_models/rnn_model')

            if epoch_idx % 5 == 0:
                print('Epoch', epoch_idx, 'Last_loss', loss_list[-1])

Solution

  • My problem was a code error in labels, they were changing between two run. So it works now. Thank you for the help