Random forest package in R shows error during prediction() if there are new factor levels present in test data. Is there any way to avoid this error?
随机森林包R显示在预测误差（）如果有新因素水平出现在测试数据。有什么方法可以避免这个错误?。
2
This research is part of Provincial Key Technologies R and D program of Heilongjiang: the study of the forest resources monitoring and management decision of spatial information technology (GC02B608).