R-如何在保持分组的同时重新排列数据框中的行？
我有以下数据框。这些行目前按物种组排序，即高粱组之后是禾本科。
# create a dataset
specie <- c(rep("sorgho" , 3) , rep("poacee" , 3) , rep("banana" , 3) , rep("triticum" , 3) )
condition <- rep(c("normal" , "stress" , "Nitrogen") , 4)
value <- abs(rnorm(12 , 0 , 15))
data <- data.frame(specie,condition,value)
print(data)
specie condition value
1 sorgho normal 12.623696
2 sorgho stress 11.394047
3 sorgho Nitrogen 0.498003
4 poacee normal 14.589322
5 poacee stress 10.744153
6 poacee Nitrogen 7.299742
7 banana normal 9.845850
8 banana stress 9.416088
9 banana Nitrogen 4.178521
10 triticum normal 13.230663
11 triticum stress 30.658355
12 triticum Nitrogen 9.402721
我怎样才能重新排列这些分组，使它们按氮值递减的顺序排列？我希望将数据框重新组织为类似于以下内容：
specie condition value
10 triticum normal 13.230663
11 triticum stress 30.658355
12 triticum Nitrogen 9.402721
4 poacee normal 14.589322
5 poacee stress 10.744153
6 poacee Nitrogen 7.299742
7 banana normal 9.845850
8 banana stress 9.416088
9 banana Nitrogen 4.178521
1 sorgho normal 12.623696
2 sorgho stress 11.394047
3 sorgho Nitrogen 0.498003
回答
我们可以按降序排列filter'Nitrogen' 行、arrange'value'，提取 'specie' 并使用它levels来`排列 'specie' 列
library(dplyr)
lvls <- data %>%
filter(condition == 'Nitrogen') %>%
arrange(desc(value)) %>%
pull(specie)
data %>%
arrange(factor(specie, levels = lvls))%>%
as_tibble
-输出
# A tibble: 12 x 3
# specie condition value
# <chr> <chr> <dbl>
# 1 triticum normal 13.2
# 2 triticum stress 30.7
# 3 triticum Nitrogen 9.40
# 4 poacee normal 14.6
# 5 poacee stress 10.7
# 6 poacee Nitrogen 7.30
# 7 banana normal 9.85
# 8 banana stress 9.42
# 9 banana Nitrogen 4.18
#10 sorgho normal 12.6
#11 sorgho stress 11.4
#12 sorgho Nitrogen 0.498
或者在单个管道中执行此操作
data %>%
arrange(factor(specie, levels =
unique(specie)[order(-value[condition == 'Nitrogen'])]))
或使用 base R
data[order(with(data, factor(specie, levels =
unique(specie)[order(-value[condition == "Nitrogen"])]))),]
数据
data <- structure(list(specie = c("sorgho", "sorgho", "sorgho", "poacee",
"poacee", "poacee", "banana", "banana", "banana", "triticum",
"triticum", "triticum"), condition = c("normal", "stress", "Nitrogen",
"normal", "stress", "Nitrogen", "normal", "stress", "Nitrogen",
"normal", "stress", "Nitrogen"), value = c(12.623696, 11.394047,
0.498003, 14.589322, 10.744153, 7.299742, 9.84585, 9.416088,
4.178521, 13.230663, 30.658355, 9.402721)), class = "data.frame",
row.names = c("1",
"2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12"))