def value(self):
        """
        Returns:
            Confustion matrix of K rows and K columns, where rows corresponds
            to ground-truth targets and columns corresponds to predicted
            targets.
        """
        if self.normalized:
            conf = self.conf.astype(np.float32)
            return conf / conf.sum(1).clip(min=1e-12)[:, None]
        else:
            return self.conf