使用 R 中的 For 循环将相同的 function 应用于数据帧中的多个变量

Question

我正在尝试在数据框中的多个变量中应用函数。 下面是我正在尝试做的一个例子。

#Creating data frame
df <- data.frame (Year = c(1,2,3),
                  "Revenue_change" = c(0.43, 0.56, 0.48),
                  "Costs_change" = c(0.31, 0.41, 0.39))

#Create vector to use for loop
var <- c("Revenue_change", "Costs_change")

#Using loop to put revenue and cost in percentage terms (multiplying by a 100)
for (v in var) { 
 df <- df %>% 
    mutate(v = v * 100)
  }

我将在更大的数据框中将其应用于多个变量，因为我无法让这个循环在我的主数据集中工作，我目前有非常重复的代码，如下所示：

KPI <- KPI %>% 

  #Total sales
  mutate(Rank_sales = rank(desc(`Total Sales_% Var`))) %>% 
  mutate(Points_sales = (n() - (Rank_sales - 1)) * 10) %>% 
  
  #Donated sales
  mutate(Rank_donated = rank(desc(`Donated Sales_% Var`))) %>% 
  mutate(Points_donated = (n() - (Rank_donated - 1)) * 10) %>% 
  
  #New good sales
  mutate(Rank_new = rank(desc(`New Goods Sales_% Var`))) %>% 
  mutate(Points_new = (n() - (Rank_new - 1)) * 10) %>% 
  
  #Gift aid
  mutate(Rank_gift = rank(desc(`Gift Aid_%`))) %>% 
  mutate(Points_gift = (n() - (Rank_gift - 1)) * 10) %>% 
  
  #Net profit
  mutate(Rank_net = rank(desc(`Net Profit_£ Var`))) %>% 
  mutate(Points_net = (n() - (Rank_net - 1)) * 10) %>% 

  #Volunteer
  mutate(Rank_volunteer = rank(desc(`Volunteer Hrs_for every £1k Sales`))) %>% 
  mutate(Points_volunteer = (n() - (Rank_volunteer - 1)) * 10)

希望循环或应用 function 将有助于减少当前代码的重复性。

Answer 1

如果没有您的实际数据样本，很难测试它是否真的有效，但这样的事情应该有效：

myvars <- c("Total Sales_% Var", "Donated Sales_% Var", "New Goods Sales_% Var", "Gift Aid_%", "Net Profit_£ Var", "Volunteer Hrs_for every £1k Sales")

Points_fun <- function(x) {
  rank_var <- rank(desc(x))
  (n() - (rank_var - 1)) * 10)
}

mutate(KPI, across(all_of(myvars), ~ rank(desc(.x)), .names = "Rank_{.col}"),
       across(all_of(myvars), Points_fun, .names = "Points_{.col}"))