帶有 dplyr 的 filter() 中的 which() 函數

Question

我正在嘗試過濾數據集，然后將異常值設置為平均值。 示例數據框：

structure(list(INDEX = c(1, 2, 3, 4, 5, 6), TARGET_WINS = c(39, 
70, 86, 70, 82, 75), TEAM_BATTING_H = c(1445, 1339, 1377, 1387, 
1297, 1279), TEAM_BATTING_2B = c(194, 219, 232, 209, 186, 200
), TEAM_BATTING_3B = c(39, 22, 35, 38, 27, 36), TEAM_BATTING_HR = c(13, 
190, 137, 96, 102, 92), TEAM_BATTING_BB = c(143, 685, 602, 451, 
472, 443), TEAM_BATTING_SO = c(842, 1075, 917, 922, 920, 973), 
    TEAM_BASERUN_SB = c(NA, 37, 46, 43, 49, 107), TEAM_BASERUN_CS = c(NA, 
    28, 27, 30, 39, 59), TEAM_BATTING_HBP = c(NA_real_, NA_real_, 
    NA_real_, NA_real_, NA_real_, NA_real_), TEAM_PITCHING_H = c(9364, 
    1347, 1377, 1396, 1297, 1279), TEAM_PITCHING_HR = c(84, 191, 
    137, 97, 102, 92), TEAM_PITCHING_BB = c(927, 689, 602, 454, 
    472, 443), TEAM_PITCHING_SO = c(5456, 1082, 917, 928, 920, 
    973), TEAM_FIELDING_E = c(1011, 193, 175, 164, 138, 123), 
    TEAM_FIELDING_DP = c(NA, 155, 153, 156, 168, 149)), row.names = c(NA, 
-6L), class = c("tbl_df", "tbl", "data.frame"))

使用dplyr ，我過濾異常值，然后嘗試根據更正后的（非異常值）均值來改變 TEAM_FIELDING_E 列：

train %>% 
  filter(which(boxplot.stats(train$TEAM_FIELDING_E)$out %in% train$TEAM_FIELDING_E, arr.ind = TRUE) == TRUE) %>% 
  mutate(
    TEAM_FIELDING_E = NA,
    TEAM_FIELDING_E = mean(train$TEAM_FIELDING_E)
  )

這將返回錯誤Error in filter_impl(.data, quo) : Result must have length 2276, not 303 （原始數據集包含 303 個TEAM_FIELDING_E異常值和 2276 行）。 我如何利用filter()這樣我的mutate()只會影響那些過濾的行？

Answer 1

在dplyr動詞中，使用裸變量名而不是使用[[或$ 。 此外，如果您嘗試過濾某個值，您可以直接過濾該值，而不是嘗試使用which來確定匹配的位置。

對於這種情況，您可以使用mutate的if_else獲得所需的內容。

out <- boxplot.stats(train$TEAM_FIELDING_E)$out

 train %>% 
  mutate(TEAM_FIELDING_E = if_else(TEAM_FIELDING_E %in% out, mean(TEAM_FIELDING_E[!(TEAM_FIELDING_E %in% out)]), TEAM_FIELDING_E))