具有重复列名的整洁 data.frame
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【中文标题】具有重复列名的整洁 data.frame【英文标题】：Tidy data.frame with repeated column names 【发布时间】：2017-06-03 08:44:07 【问题描述】：我有一个程序可以提供这种格式的数据
toy
file_path Condition Trial.Num A B C ID A B C ID A B C ID
1 root/some.extension Baseline 1 2 3 5 car 2 1 7 bike 4 9 0 plane
2 root/thing.extension Baseline 2 3 6 45 car 5 4 4 bike 9 5 4 plane
3 root/else.extension Baseline 3 4 4 6 car 7 5 4 bike 68 7 56 plane
4 root/uniquely.extension Treatment 1 5 3 7 car 1 7 37 bike 9 8 7 plane
5 root/defined.extension Treatment 2 6 7 3 car 4 6 8 bike 9 0 8 plane
我的目标是将格式整理成至少可以更容易通过具有唯一列名的 reshape 进行整理
tidy_toy
file_path Condition Trial.Num A B C ID
1 root/some.extension Baseline 1 2 3 5 car
2 root/thing.extension Baseline 2 3 6 45 car
3 root/else.extension Baseline 3 4 4 6 car
4 root/uniquely.extension Treatment 1 5 3 7 car
5 root/defined.extension Treatment 2 6 7 3 car
6 root/some.extension Baseline 1 2 1 7 bike
7 root/thing.extension Baseline 2 5 4 4 bike
8 root/else.extension Baseline 3 7 5 4 bike
9 root/uniquely.extension Treatment 1 1 7 37 bike
10 root/defined.extension Treatment 2 4 6 8 bike
11 root/some.extension Baseline 1 4 9 0 plane
12 root/thing.extension Baseline 2 9 5 4 plane
13 root/else.extension Baseline 3 68 7 56 plane
14 root/uniquely.extension Treatment 1 9 8 7 plane
15 root/defined.extension Treatment 2 9 0 8 plane
如果我尝试从toy 到melt，它不起作用，因为只有第一个 ID 列将用于id.vars（因此所有内容都会被标记为汽车）。相同的变量将被删除。
这是两个表的输出
structure(list(file_path = structure(c(3L, 4L, 2L, 5L, 1L), .Label = c("root/defined.extension",
"root/else.extension", "root/some.extension", "root/thing.extension",
"root/uniquely.extension"), class = "factor"), Condition = structure(c(1L,
1L, 1L, 2L, 2L), .Label = c("Baseline", "Treatment"), class = "factor"),
Trial.Num = c(1L, 2L, 3L, 1L, 2L), A = 2:6, B = c(3L, 6L,
4L, 3L, 7L), C = c(5L, 45L, 6L, 7L, 3L), ID = structure(c(1L,
1L, 1L, 1L, 1L), .Label = "car", class = "factor"), A = c(2L,
5L, 7L, 1L, 4L), B = c(1L, 4L, 5L, 7L, 6L), C = c(7L, 4L,
4L, 37L, 8L), ID = structure(c(1L, 1L, 1L, 1L, 1L), .Label = "bike", class = "factor"),
A = c(4L, 9L, 68L, 9L, 9L), B = c(9L, 5L, 7L, 8L, 0L), C = c(0L,
4L, 56L, 7L, 8L), ID = structure(c(1L, 1L, 1L, 1L, 1L), .Label = "plane", class = "factor")), .Names = c("file_path",
"Condition", "Trial.Num", "A", "B", "C", "ID", "A", "B", "C",
"ID", "A", "B", "C", "ID"), class = "data.frame", row.names = c(NA,
-5L))
structure(list(file_path = structure(c(3L, 4L, 2L, 5L, 1L, 3L,
4L, 2L, 5L, 1L, 3L, 4L, 2L, 5L, 1L), .Label = c("root/defined.extension",
"root/else.extension", "root/some.extension", "root/thing.extension",
"root/uniquely.extension"), class = "factor"), Condition = structure(c(1L,
1L, 1L, 2L, 2L, 1L, 1L, 1L, 2L, 2L, 1L, 1L, 1L, 2L, 2L), .Label = c("Baseline",
"Treatment"), class = "factor"), Trial.Num = c(1L, 2L, 3L, 1L,
2L, 1L, 2L, 3L, 1L, 2L, 1L, 2L, 3L, 1L, 2L), A = c(2L, 3L, 4L,
5L, 6L, 2L, 5L, 7L, 1L, 4L, 4L, 9L, 68L, 9L, 9L), B = c(3L, 6L,
4L, 3L, 7L, 1L, 4L, 5L, 7L, 6L, 9L, 5L, 7L, 8L, 0L), C = c(5L,
45L, 6L, 7L, 3L, 7L, 4L, 4L, 37L, 8L, 0L, 4L, 56L, 7L, 8L), ID = structure(c(2L,
2L, 2L, 2L, 2L, 1L, 1L, 1L, 1L, 1L, 3L, 3L, 3L, 3L, 3L), .Label = c("bike",
"car", "plane"), class = "factor")), .Names = c("file_path",
"Condition", "Trial.Num", "A", "B", "C", "ID"), class = "data.frame", row.names = c(NA,
-15L))
【问题讨论】：
【参考方案1】：您可以使用make.unique-函数来创建唯一的列名。之后，您可以使用data.table-package 中的melt，它能够基于列名中的patterns 创建多个值列：
# make the column names unique
names(toy) <- make.unique(names(toy))
# let the 'Condition' column start with a small letter 'c'
# so it won't be detected by the patterns argument from melt
names(toy)[2] <- tolower(names(toy)[2])
# load the 'data.table' package
library(data.table)
# tidy the data into long format
tidy_toy <- melt(setDT(toy),
measure.vars = patterns('^A','^B','^C','^ID'),
value.name = c('A','B','C','ID'))
给出：
> tidy_toy
file_path condition Trial.Num variable A B C ID
1: root/some.extension Baseline 1 1 2 3 5 car
2: root/thing.extension Baseline 2 1 3 6 45 car
3: root/else.extension Baseline 3 1 4 4 6 car
4: root/uniquely.extension Treatment 1 1 5 3 7 car
5: root/defined.extension Treatment 2 1 6 7 3 car
6: root/some.extension Baseline 1 2 2 1 7 bike
7: root/thing.extension Baseline 2 2 5 4 4 bike
8: root/else.extension Baseline 3 2 7 5 4 bike
9: root/uniquely.extension Treatment 1 2 1 7 37 bike
10: root/defined.extension Treatment 2 2 4 6 8 bike
11: root/some.extension Baseline 1 3 4 9 0 plane
12: root/thing.extension Baseline 2 3 9 5 4 plane
13: root/else.extension Baseline 3 3 68 7 56 plane
14: root/uniquely.extension Treatment 1 3 9 8 7 plane
15: root/defined.extension Treatment 2 3 9 0 8 plane
另一种选择是使用measure.vars 的列索引列表：
tidy_toy <- melt(setDT(toy),
measure.vars = list(c(4,8,12), c(5,9,13), c(6,10,14), c(7,11,15)),
value.name = c('A','B','C','ID'))
那么就没有必要让列名唯一了。
一种更复杂的方法，可以创建更容易被patterns 参数区分的名称：
# select the names that are not unique
tt <- table(names(toy))
idx <- which(names(toy) %in% names(tt)[tt > 1])
nms <- names(toy)[idx]
# make them unique
names(toy)[idx] <- paste(nms,
rep(seq(length(nms) / length(names(tt)[tt > 1])),
each = length(names(tt)[tt > 1])),
sep = '.')
# your columnnames are now unique:
> names(toy)
[1] "file_path" "Condition" "Trial.Num" "A.1" "B.1" "C.1" "ID.1" "A.2"
[9] "B.2" "C.2" "ID.2" "A.3" "B.3" "C.3" "ID.3"
# tidy the data into long format
tidy_toy <- melt(setDT(toy),
measure.vars = patterns('^A.\\d','^B.\\d','^C.\\d','^ID.\\d'),
value.name = c('A','B','C','ID'))
这将给出相同的最终结果。
正如 cmets 中提到的，janitor-package 也可以帮助解决这个问题。 clean_names() 的工作原理与 make.unique 函数类似。 See here 解释一下。
【讨论】：
这个很有创意！我将尝试使用变量的模式（我的原始数据中的列比 A、B、C 多） 我是janitor 用于清理数据帧的软件包的忠实粉丝。对这种情况有帮助。【参考方案2】：
使用 tidyverse 我们可以做到：
library(tidyverse)
toy %>%
repair_names(sep="_") %>%
pivot_longer(-(1:3),names_to = c(".value","id"), names_sep="_") %>%
select(-id)
#> # A tibble: 15 x 7
#> file_path Condition Trial.Num A B C ID
#> <fct> <fct> <int> <int> <int> <int> <fct>
#> 1 root/some.extension Baseline 1 2 3 5 car
#> 2 root/some.extension Baseline 1 2 1 7 bike
#> 3 root/some.extension Baseline 1 4 9 0 plane
#> 4 root/thing.extension Baseline 2 3 6 45 car
#> 5 root/thing.extension Baseline 2 5 4 4 bike
#> 6 root/thing.extension Baseline 2 9 5 4 plane
#> 7 root/else.extension Baseline 3 4 4 6 car
#> 8 root/else.extension Baseline 3 7 5 4 bike
#> 9 root/else.extension Baseline 3 68 7 56 plane
#> 10 root/uniquely.extension Treatment 1 5 3 7 car
#> 11 root/uniquely.extension Treatment 1 1 7 37 bike
#> 12 root/uniquely.extension Treatment 1 9 8 7 plane
#> 13 root/defined.extension Treatment 2 6 7 3 car
#> 14 root/defined.extension Treatment 2 4 6 8 bike
#> 15 root/defined.extension Treatment 2 9 0 8 plane
#> Warning message:
#> Expected 2 pieces. Missing pieces filled with `NA` in 4 rows [1, 2, 3, 4].
【讨论】：
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