'Args:
pred (np.ndarray): binary array.
label (np.ndarray): binary array of the same size.'

def feed(self, pred, label):

    assert (pred.shape == label.shape), '{}    !=    {}'.format(pred.shape, label.shape)
    self.nr_pos += (label == 1).sum()
    self.nr_neg += (label == 0).sum()
    self.nr_pred_pos += (pred == 1).sum()
    self.nr_pred_neg += (pred == 0).sum()
    self.corr_pos += ((pred == 1) & (pred == label)).sum()
    self.corr_neg += ((pred == 0) & (pred == label)).sum()
