models_siamese.py 文件源码

def fit(self, train_data, train_labels, val_data, val_labels):
        t_process, t_wall = time.process_time(), time.time()
        sess = tf.Session(graph=self.graph)
        shutil.rmtree(self._get_path('summaries'), ignore_errors=True)
        writer = tf.summary.FileWriter(self._get_path('summaries'), self.graph)
        shutil.rmtree(self._get_path('checkpoints'), ignore_errors=True)
        os.makedirs(self._get_path('checkpoints'))
        path = os.path.join(self._get_path('checkpoints'), 'model')
        sess.run(self.op_init)

        # Training.
        accuracies = []
        losses = []
        indices = collections.deque()
        num_steps = int(self.num_epochs * train_data.shape[0] / self.batch_size)
        for step in range(1, num_steps+1):

            # Be sure to have used all the samples before using one a second time.
            if len(indices) < self.batch_size:
                indices.extend(np.random.permutation(train_data.shape[0]))
            idx = [indices.popleft() for i in range(self.batch_size)]

            batch_data, batch_labels = train_data[idx, :, :, :], train_labels[idx]
            if type(batch_data) is not np.ndarray:
                batch_data = batch_data.toarray()  # convert sparse matrices
            feed_dict = {self.ph_data: batch_data, self.ph_labels: batch_labels, self.ph_dropout: self.dropout}
            learning_rate, loss_average = sess.run([self.op_train, self.op_loss_average], feed_dict)

            # Periodical evaluation of the model.
            if step % self.eval_frequency == 0 or step == num_steps:
                epoch = step * self.batch_size / train_data.shape[0]
                print('step {} / {} (epoch {:.2f} / {}):'.format(step, num_steps, epoch, self.num_epochs))
                print('  learning_rate = {:.2e}, loss_average = {:.2e}'.format(learning_rate, loss_average))

                string, auc, loss, scores_summary = self.evaluate(train_data, train_labels, sess)
                print('  training {}'.format(string))

                string, auc, loss, scores_summary = self.evaluate(val_data, val_labels, sess)
                print('  validation {}'.format(string))
                print('  time: {:.0f}s (wall {:.0f}s)'.format(time.process_time()-t_process, time.time()-t_wall))

                accuracies.append(auc)
                losses.append(loss)

                # Summaries for TensorBoard.
                summary = tf.Summary()
                summary.ParseFromString(sess.run(self.op_summary, feed_dict))
                summary.value.add(tag='validation/auc', simple_value=auc)
                summary.value.add(tag='validation/loss', simple_value=loss)
                writer.add_summary(summary, step)

                # Save model parameters (for evaluation).
                self.op_saver.save(sess, path, global_step=step)

        print('validation accuracy: peak = {:.2f}, mean = {:.2f}'.format(max(accuracies), np.mean(accuracies[-10:])))
        writer.close()
        sess.close()

        t_step = (time.time() - t_wall) / num_steps
        return accuracies, losses, t_step, scores_summary