R中的条件计算基于行值和类别

时间:2017-10-11 14:51:29

标签: r data-manipulation categorical-data calculation

我有这个数据框:

df<-data.frame(a=c("a1","a2","a3","a4","b1","b2","b3","b4","a1","a2","a3","a4","b1","b2","b3","b4"), b=c("x1","x2","x3","total","x1","x2","x3","total", "x1","x2","x3","total","x1","x2","x3","total"), reg=c("A","A","A","A","A","A","A","A","B", "B","B","B","B","B","B","B"), c=c(1:16))

看起来像:

    a     b reg  c
1  a1    x1   A  1
2  a2    x2   A  2
3  a3    x3   A  3
4  a4 total   A  4
5  b1    x1   A  5
6  b2    x2   A  6
7  b3    x3   A  7
8  b4 total   A  8
9  a1    x1   B  9
10 a2    x2   B 10
11 a3    x3   B 11
12 a4 total   B 12
13 b1    x1   B 13
14 b2    x2   B 14
15 b3    x3   B 15
16 b4 total   B 16

列&#39; a&#39;,&#39; b&#39;和&#39; reg&#39;是分类变量。我想要做的是创建一个新的列,它划分x(i),其中i = 1,2,3与&#39; total&#39; reg' and in a&#39;中每个类别的(x(i)/ total)列。

有人可以帮我吗?

2 个答案:

答案 0 :(得分:1)

假设您的df是按照您的示例订购的。

library(zoo)
df$NEW=df$c
df$NEW[df$b!='total']=NA
df$NEW=na.locf(df$NEW,fromLast=T,na.rm=F)
df$NEW=df$c/df$NEW

df
    a     b reg  c       NEW
1  a1    x1   A  1 0.2500000
2  a2    x2   A  2 0.5000000
3  a3    x2   A  3 0.7500000
4  a4 total   A  4 1.0000000
5  b1    x1   A  5 0.6250000
6  b2    x2   A  6 0.7500000
7  b3    x2   A  7 0.8750000
8  b4 total   A  8 1.0000000
9  a1    x1   B  9 0.7500000
10 a2    x2   B 10 0.8333333
11 a3    x2   B 11 0.9166667
12 a4 total   B 12 1.0000000
13 b1    x1   B 13 0.8125000
14 b2    x2   B 14 0.8750000
15 b3    x2   B 15 0.9375000
16 b4 total   B 16 1.0000000

根据Op的解释,以下是他/她的真实数据。(来自OP)

data1$shares<-NA 
id<-which(data1$Occupation=='Total') 
data1$shares[id]<-data1$2014[id]
data1$shares=na.locf(data1$shares,fromLast=T,na.rm=F) 
data1$shares=data1$2014/data1$shares

答案 1 :(得分:0)

只需使用R base:

df<-data.frame(a=c("a1","a2","a3","a4","b1","b2","b3","b4","a1","a2","a3","a4","b1","b2","b3","b4"), b=c("x1","x2","x3","total","x1","x2","x3","total", "x1","x2","x3","total","x1","x2","x3","total"), reg=c("A","A","A","A","A","A","A","A","B", "B","B","B","B","B","B","B"), c=c(1:16))

totals <- data.frame(To=df[df$b=='total',4])
totals$from <- c(1, totals$To[1:nrow(totals)-1]+1)
df$NEW = df$c/totals[findInterval(x=df$c, vec=c(rbind(totals$from, totals$to))), 1]
df

输出:

    a     b reg  c       NEW
1  a1    x1   A  1 0.2500000
2  a2    x2   A  2 0.5000000
3  a3    x3   A  3 0.7500000
4  a4 total   A  4 1.0000000
5  b1    x1   A  5 0.6250000
6  b2    x2   A  6 0.7500000
7  b3    x3   A  7 0.8750000
8  b4 total   A  8 1.0000000
9  a1    x1   B  9 0.7500000
10 a2    x2   B 10 0.8333333
11 a3    x3   B 11 0.9166667
12 a4 total   B 12 1.0000000
13 b1    x1   B 13 0.8125000
14 b2    x2   B 14 0.8750000
15 b3    x3   B 15 0.9375000
16 b4 total   B 16 1.0000000