R创建重复列(bulk)

Question

如何基于colname模式创建多个重复列?我的实际数据帧非常大，所以我需要一个循环或其他一些有效的代码。

df <- data.frame(x001 = c(1,2,3), x002 = c(3,4,5), x003 = c(6,7,8), soccer = c(700,600,300), volley = c(30,22,29))
df
#current df
#   x001 x002 x003 soccer volley
#   1    3    6    700     30
#   2    4    7    600     22
#   3    5    8    300     29
#desired output: all x00 columns need to be duplicated and get a "no2" addition to their name. 
#   x001 x002 x003 soccer volley  x001no2 x002no2 x003no2
#   1    3    6    700     30       1        3    6  
#   2    4    7    600     22       2        4    7 
#   3    5    8    300     29       3        5    8 

Answer 1

简单

tmp=grep("x00",colnames(df))
cbind(
df,
setNames(df[,tmp],paste0(colnames(df)[tmp],"no2"))
)
x001 x002 x003 soccer volley x001no2 x002no2 x003no2
1    1    3    6    700     30       1       3       6
2    2    4    7    600     22       2       4       7
3    3    5    8    300     29       3       5       8

Answer 2

使用dplyr和stringr:

library(dplyr)
library(stringr)
df %>% bind_cols(df %>% select(starts_with('x00')) %>% rename_all( ~ str_c(., 'no2')) )
x001 x002 x003 soccer volley x001no2 x002no2 x003no2
1    1    3    6    700     30       1       3       6
2    2    4    7    600     22       2       4       7
3    3    5    8    300     29       3       5       8

Answer 3

数据。表解决方案:

# Import and initialise the data.table package: 
library(data.table)
# Resolve the column names desired to be replicated: 
# df_names => character vectors
df_names <- grep(
"^x\d+",
colnames(df),
value = TRUE
)
# Replicate the desired vectors: res => data.table
res <- setDT(df)[, paste0(
df_names,
"no2"
) := df[
, .SD,
.SDcols = df_names
],
]

Tidyverse解决方案:

# Import and initialise the tidyverse package: 
library(tidyverse)
# Replicate the desired column vectors: res => data.frame
res <- df %>% 
bind_cols(
.,
df %>% 
select_if(
str_detect(
colnames(.),
"^x\d+"
)
) %>% 
set_names(
.,
str_c(
colnames(.),
"no2"
)
)
)