Question

假设我有以下数据框：

tmp <- data.frame(
code = c("11","111","112"),
label = c("sector a","industry a1","industry a2"),
sector = c("11","11","11"),
industry = c("NA","111","112")
)

这样：

> tmp
  code       label sector industry
1   11    sector a     11       NA
2  111 industry a1     11      111
3  112 industry a2     11      112

我想创建一个带有扇区标签的变量。在这个简单的例子中，所有行业都属于同一部门，所以

> tmp$sector.alpha <- c(rep("sector a",3))

可以生成：

> tmp
  code       label sector industry sector.alpha
1   11    sector a     11       NA     sector a
2  111 industry a1     11      111     sector a
3  112 industry a2     11      112     sector a

但是假设一个更复杂的例子，其中有两个或更多个部门，每个部门有任意数量的行业。

如何生成正确的标签？

Answer 1

例如：

 ddply(tmp,.(sector),transform,sector.alpha=label[1])
  code       label sector industry sector.alpha
1   11    sector a     11       NA     sector a
2  111 industry a1     11      111     sector a
3  112 industry a2     11      112     sector a

更改一点数据以引入更多扇区：

tmp <- data.frame(
  code = c("11","111","112","121"),
  label = c("sector a","industry a1","industry a2","indstry 14"),
  sector = c("11","11","12","12"),
  industry = c("NA","111","112","212")
)

library(plyr)
ddply(tmp,.(sector),transform,sector.alpha=label[1])

 code       label sector industry sector.alpha
1   11    sector a     11       NA     sector a
2  111 industry a1     11      111     sector a
3  112 industry a2     12      112  industry a2
4  121  indstry 14     12      212  industry a2

Answer 2

可以使用 cut 命令将数字变量转换为具有多个类别的分类变量。使用？cut命令的详细信息。让我们尝试以下代码。

x<-sample(0:100,10) #Generates random data between 0 and 100 of size 10

cat<-cut(x,breaks=c(0,40,50,60,70,80,100),labels=c("a","b","c","d","e","f"))

剪切命令中断您想要的变量，标签在中断中定义的相应类间隔。这可能有所帮助。您可以对数据框执行相同的操作

x<-sample(0:100,10)
y<-sample(200:300,10)
dat<-data.frame(x,y)
dat$cat<-cut(x,breaks=c(0,40,50,60,70,80,100),labels=c("a","b","c","d","e","f"))

Answer 3

这也有效：

tmp$sector.a <- tmp[match(tmp$sector,tmp$code),"label"]

使用一致性替换数据框中的值

3 个答案: