import tensorflow as tf

    pairwise_improvement_bool = tf.cast(pairwise_improvement > 0, pairwise_improvement.dtype)
    self.pairwise_improvement_bool = pairwise_improvement_bool

    metrics.append(tf.summary.scalar('training/avg_dist', mean_dist))
    metrics.append(tf.summary.scalar('training/pred_dist', mean_pred_error))
    metrics.append(tf.summary.scalar('training/improvement', improvement))
    metrics.append(tf.summary.scalar('training/improvement_abs', tf.nn.relu(improvement)))
    metrics.append(tf.summary.histogram('training/improvement_abs_hist', nut.nan_to_zero(improvement)))
