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r - 有没有办法在 for 循环中为数据框赋值？

问题描述

我想使用 for 循环将值分配给数据帧，该循环遍历数据帧中的不同行。

我试图将我需要的变量名称（在每次迭代中都会发生变化）分配给一些值，然后将这些值放在一个数据框中，但这不起作用

banks <- read.csv("banks_csv.csv", sep = ";", stringsAsFactors = FALSE)
banks<-data.frame(banks)

for (row in 1:nrow(banks)){
bank = banks[row, "Company"]

reviews <- read.csv(paste(bank, "_cleaned.csv", sep = ""))
reviews$X = NULL
reviews_summary <- reviews %>% 
group_by(Year_Quarter) %>%     
    summarise(rat_gen = mean(rat_general, na.rm = TRUE), 
              CV = mean(rat_CV, na.rm = TRUE), 
              WL = mean(rat_WL, na.rm = TRUE), 
              CO = mean(rat_CO, na.rm = TRUE), 
              CB = mean(rat_CB, na.rm = TRUE), 
              SM = mean(rat_SM, na.rm = TRUE)) 

nam <- paste("general_", bank, sep = "")
assign(nam, reviews_summary$rat_gen)

nam <- paste("CV_", bank, sep = "")
assign(nam, reviews_summary$CV)

nam <- paste("WL_", bank, sep = "")
assign(nam, reviews_summary$WL)

nam <- paste("CO_", bank, sep = "")
as.list(nam, reviews_summary$CO)

nam <- paste("CB_", bank, sep = "")
as.list(nam, reviews_summary$CB)

nam <- paste("SM_", bank, sep = "")
as.list(nam, reviews_summary$SM)

df <- data.frame(paste("general_", bank, sep = ""), paste("CV_", bank, sep = ""), paste("WL_", bank, sep = ""), paste("CO_", bank, sep = ""), paste("CB_", bank, sep = ""), paste("SM_", bank, sep = ""))
}

编辑：我希望只有一个 data.frame，每次迭代添加 6 列，而不是为每次迭代生成一个数据框。

标签： rdataframefor-loopassign

解决方案

也许这就是你要找的。rename您可以使用以下函数重命名列：

for (row in 1:nrow(banks)){
  bank = banks[row, "Company"]
  reviews <- read.csv(paste(bank, "_cleaned.csv", sep = ""))

  df_bank <- reviews %>% 
    group_by(Year_Quarter) %>%     
    summarise(general = mean(rat_general, na.rm = TRUE), 
              CV = mean(rat_CV, na.rm = TRUE), 
              WL = mean(rat_WL, na.rm = TRUE), 
              CO = mean(rat_CO, na.rm = TRUE), 
              CB = mean(rat_CB, na.rm = TRUE), 
              SM = mean(rat_SM, na.rm = TRUE)) %>% 
    rename_at(-1, ~paste0(.x, "_", bank)) %>% 
    as.data.frame()

  df <- cbind(df, df_bank)
 }

请注意，您必须df在开始循环之前初始化以获得正确的行数。

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