练习knn的时候出现问题

tseen

最近在按《机器学习与r语言》这本书学习r。
学习knn的时候跑书上的例子成功，于是自己生成了一个文件想练习下。文件见附件。
运行后出现错误，不知道为什么，向大家请教下。代码和错误信息如下

> sj<-read.csv('sjknn.csv',stringsAsFactors=F)
> sj<-sj[-1]
> sj$v5<-factor(sj$v5,levels = c("high","low"),labels = c("高于中值","低于中值"))
> sj_train<-sj[1:1000,]
> sj_test<-sj[1001:1146,]
> sj_train_lables<-sj_train$v5
> sj_test_prep<-knn(train = sj_train,test = sj_test,cl=sj_train_lables,k=34)
Error in knn(train = sj_train, test = sj_test, cl = sj_train_lables, k = 34) :
  NA/NaN/Inf in foreign function call (arg 6)
In addition: Warning messages:
1: In knn(train = sj_train, test = sj_test, cl = sj_train_lables, k = 34) :
  NAs introduced by coercion
2: In knn(train = sj_train, test = sj_test, cl = sj_train_lables, k = 34) :
  NAs introduced by coercion
问题已经解决，应该把v5去除