在 R 中，如何在变量之后命名数据帧列?

Question

作为函数的一部分，我正在尝试创建一个数据帧，我想以变量命名其中一列。下面是一些虚拟数据，是我坚持的部分。

library(tidyverse)
graph <-  data.frame(brand = rep(c("A","B","C"), each = 3),
week_commencing = rep(as.Date(c('2020-03-01', '2020-04-01', '2020-05-01')), times = 3),
sessions = sample(1000:2000,9),
conv_rate = runif(9,0,1))
website = "A"
metric = "sessions"
graph %>% 
filter(brand == (!!website)) %>%
group_by(brand) %>% 
summarise(metric = max(get(metric)),
week_commencing = min(week_commencing),
lab = "This Year") 

在总结函数调用中，我希望将列名指标称为会话，我尝试使用 get(metric( 和 (！！度量(作为列命名的一部分，但它不起作用。

这甚至可以在 R 中做到吗？任何帮助将不胜感激。

Answer 1

如果您希望在dplyr函数的左侧使用变量作为名称(而无需单独重命名列(，则可以使用!!variable :=而不是variable =，因此在您的情况下，它将是：

graph %>% 
filter(brand == (!!website)) %>%
group_by(brand) %>% 
summarise(!!metric := max(get(metric)),
week_commencing = min(week_commencing),
lab = "This Year") 
#> # A tibble: 1 x 4
#>   brand sessions week_commencing lab      
#>  <chr>    <int> <date>          <chr>    
#> 1 A         1901 2020-03-01      This Year

Answer 2

你的意思是这样吗？

library(tidyverse)
graph <-  data.frame(brand = rep(c("A","B","C"), each = 3),
week_commencing = rep(as.Date(c('2020-03-01', '2020-04-01', '2020-05-01')), times = 3),
sessions = sample(1000:2000,9),
conv_rate = runif(9,0,1))
website = "A"
metric = "sessions"
graph %>% 
filter(brand == (!!website)) %>%
group_by(brand) %>% 
summarise(metric = max(get(metric)),
week_commencing = min(week_commencing),
lab = "This Year") %>% rename(sessions=metric)
# A tibble: 1 x 4
brand sessions week_commencing lab      
<fct>    <int> <date>          <chr>    
1 A         1819 2020-03-01      This Year

Answer 3

我们也可以用

library(dplyr)   
graph %>%
filter(brand == website) %>%
group_by(brand) %>% 
summarise(metric = max(!! rlang::sym(metric)),
week_commencing = min(week_commencing),
lab = "This Year") %>% rename_at(vars(metric), ~ 'sessions')
# A tibble: 1 x 4
brand sessions week_commencing lab      
<chr>    <int> <date>          <chr>    
1 A         1555 2020-03-01      This Year