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我正在尝试构建一个由三个字符变量和一个数字变量组成的数据框。当我运行以下代码时，我得到一个四列矩阵，但分数变量不再是数字，分数被视为因素。

school<-c("NYU", "BYU", "USC", "FIT", "UNH","UCLA","USF","Columbia")
state<-c("NY","UT","CA","NY","NY","CA", "CA","NY")
measure<-c("MSAT","MSAT","GPA","MSAT","MSAT","GPA","GPA","GPA")
score<-c(500, 490, 2.9, 759, 550, 1.2, 3.1, 3.2)
data<-cbind(school,state, measure,score)

如果我跑

data1<-data.frame(cbind(school,state, measure,score))

我得到一个score仍然是一个因素的数据框。我怎样才能建立这个数据框，以便它score是数字的？

4

2 回答 2

6

要构建由三个字符变量和一个数值变量组成的数据框，您需要指定：stringsAsFactors=FALSE在data.frame()函数中：

school<-c("NYU", "BYU", "USC")
state<-c("NY","UT","CA")
measure<-c("MSAT","MSAT","GPA")
score<-c(500, 490, 2.9)
df<-data.frame(school,state, measure,score,  stringsAsFactors=FALSE)

结果如下：

summary(df)
school             state             measure              score      
Length:3           Length:3           Length:3           Min.   :  2.9  
Class :character   Class :character   Class :character   1st Qu.:246.4  
Mode  :character   Mode  :character   Mode  :character   Median :490.0  
                                                         Mean   :331.0  
                                                         3rd Qu.:495.0  
                                                         Max.   :500.0
于 2018-03-20T23:18:59.467 回答
3 
 school<-c("NYU", "BYU", "USC", "FIT", "UNH","UCLA","USF","Columbia")
 state<-c("NY","UT","CA","NY","NY","CA", "CA","NY")
 measure<-c("MSAT","MSAT","GPA","MSAT","MSAT","GPA","GPA","GPA")
 score<-c(500, 490, 2.9, 759, 550, 1.2, 3.1, 3.2)
 data<-data.frame(school,state, measure,score)
 data
   school state measure score
     NYU    NY    MSAT 500.0
     BYU    UT    MSAT 490.0
     USC    CA     GPA   2.9
     FIT    NY    MSAT 759.0
     UNH    NY    MSAT 550.0
    UCLA    CA     GPA   1.2
     USF    CA     GPA   3.1
Columbia    NY     GPA   3.2

is.numeric(data$score)
[1] TRUE

我想这应该工作！

于 2014-07-23T03:30:34.650 回答