这可能是因为结果因子水平为0"和1".

It is probably due to having about outcome factor with levels "0" and "1".

发生这种情况时会发出特定警告:至少一个类级别不是有效的 R 变量名称；如果生成类概率，这可能会导致错误，因为变量名称将转换为:X0, X1"

There is a specific warning issued when this happens: At least one of the class levels are not valid R variables names; This may cause errors if class probabilities are generated because the variables names will be converted to: X0, X1"

似乎人们一致忽略警告，所以我打算在下一个版本中抛出一个错误.

It seems that people uniformly ignore warnings so I'm going to make this throw an error in the next version.