r怎么把data.frame的因子向量转化为字符

Question

如题所述

Answer 1

1、向量到因子转换
实际上就是构造因子，例如上例：

>qulity<-c('good','common','good','better','excellent')
> q<-factor(qulity,levels=c('bad','good','common','better','excellent'),
+ labels=c('bad','good','common','better','excellent'),order=TRUE)
> str(q)
Ord.factor w/ 5 levels "bad"<"common"<..: 3 2 3 4 5

2、因子到向量的转换
（1）使用as.vector()函数，例子：
> q<-factor(qulity,levels=c('bad','common','good','better','excellent'),
+ labels=c('bad','common','good','better','excellent'),order=TRUE)
> q
[1] good common good better excellent
Levels: bad < common < good < better < excellent
> str(q)
Ord.factor w/ 5 levels "bad"<"common"<..: 3 2 3 4 5

> q2<-as.vector(q)
> q2
[1] "good" "common" "good" "better" "excellent"
> str(q2)
chr [1:5] "good" "common" "good" "better" "excellent"
可以看到已经转换为字符型。
（2）使用as.numeric()函数，因子被转换为数字，例子：
> q2<-as.numeric(q)
> q2
[1] 3 2 3 4 5
> str(q2)
num [1:5] 3 2 3 4 5本回答被提问者采纳