Returns recall (number of positive examples) in the top k
    If value is False then counts number of negative examples
    TODO: add prop argument to return recall proportion instead of count

def recall(y_true, y_score, k=None, value=True):
    """
    Returns recall (number of positive examples) in the top k
    If value is False then counts number of negative examples
    TODO: add prop argument to return recall proportion instead of count
    """
    y_true, y_score = to_float(y_true, y_score)
    top = _argtop(y_score, k)

    if not value:
        y_true = 1-y_true

    r = np.nan_to_num(y_true[top]).sum()

    return r