通过过滤、分组然后以语句为条件重命名因子级别

Question

我有一个这样的数据框：

 data<- data.frame(ID= seq(1,12, 1), 
                   plantfam= c(1,1,2,2,1,1,1,1,2,2,3,3), 
                   lepsp= c(rep("A", 4), "B", "B", rep("C", 6)), 
                   needsmorpho= c(rep("yes", 4),"no", "no", rep("yes", 6)))

我需要先过滤所有 needsmorpho，即 yes。然后我需要将所有 lepsp 与相同的 plantfam 分组。对于每个独特的 lepsp 和 plantfam 匹配，lepsp 将被赋予一个独特的形态物种名称。为了制作一个 morphosp 名称，我想粘贴 morphosp 和一个基于唯一的 lepsp 和 plantfam 匹配的唯一编号。输出将是：

output<- data.frame(ID= seq(1,12, 1), 
                   plantfam= c(1,1,2,2,1,1,1,1,2,2,3,3), 
                   lepsp= c("A_morpho1","A_morpho1","A_morpho2","A_morpho2",
                         "B","B","C_morpho1","C_morpho1",
                         "C_morpho2","C_morpho2","C_morpho3","C_morpho3"), 
                   needsmorpho= c(rep("yes", 4),"no", "no", rep("yes", 6)))

我试过：

subset1 <- 
 file %>% 
 filter(NeedsMorpho == "yes") %>% 
 group_by(lepsp) %>%  
 mutate(lepsp = 
 paste0(lepsp,"_morphosp",match(plantfam,unique(plantfam))))

subset2 <- 
file %>% 
filter(NeedsMorpho == "yes") %>% 
setdiff(file, .)

file<-union(subset1, subset2) %>% arrange(lepsp)

Answer 1

这是否实现了您的目标？

library( data.table )
setDT(data)
data[ needsmorpho == "yes", lepsp := paste0(lepsp,"_morphosp",plantfam) ]

Answer 2

使用 dplyr 中的 case_when，您可以执行以下操作：

library(tidyverse)

data %>% 
  mutate(lepsp = case_when(needsmorpho == "yes" ~ paste0(lepsp, "_morpho", plantfam),
                           TRUE ~ as.character(lepsp)))

哪个returns:

   ID plantfam     lepsp needsmorpho
1   1        1 A_morpho1         yes
2   2        1 A_morpho1         yes
3   3        2 A_morpho2         yes
4   4        2 A_morpho2         yes
5   5        1         B          no
6   6        1         B          no
7   7        1 C_morpho1         yes
8   8        1 C_morpho1         yes
9   9        2 C_morpho2         yes
10 10        2 C_morpho2         yes
11 11        3 C_morpho3         yes
12 12        3 C_morpho3         yes

通过过滤、分组然后以语句为条件重命名因子级别

Rename levels of factor by filtering, grouping then conditional on statement

r

tidyverse