过滤列中的值并删除不符合条件的行

Question

我在 R 中相对较新。 我有这个问题。 我有狗的数据有用部分的数据示例（使用列 age_month 和 rasnaam（品种））

如果它们是小型、中型、大型等，我必须查找所有品种。如果它们是小型品种，则必须删除 age_month 低于 9 的所有行，如果它们是 age_month 的中型品种行低于 13 必须删除，（大，age_month < 24）。 我已经尝试了一些东西，但它不会工作。 我已将所有狗添加到列表中（也使用矢量尝试过），如下所示：（仅适用于此处的小型犬）

small_dogs <- list("Affenpinscher", "Bichon frisé", "Bolognezer", "Chihuahua, langhaar",
            "Dandie Dinmont Terrier", "Dwergkeeshond", "Japanse Spaniel",
            "Griffon belge", "Griffon bruxellois", "Kleine Keeshond", 
            "Lhasa Apso", "Maltezer", "Mopshond", "Pekingees", "Petit Brabançon",
            "Shih Tzu", "Tibetaanse Spaniel", "Volpino Italiano", "Yorkshire Terrier")

我试过这个：

for (i in 1:nrow(brachquest2)){
     ifelse((brachquest2$rasnaam %in% small_dogs), (brachquest2 <- brachquest2[!(brachquest2$age_month < 9), ]), 
     ifelse((brachquest2$rasnaam %in% medium_dogs)), (brachquest2 <- brachquest2[!(brachquest2$age_month < 13), ]), 
     (brachquest2 <- brachquest2[!(brachquest2$age_month < 24), ]))
            }

但后来我得到一个未使用的 arguments 错误。 然后我尝试使用case_when()，但是我对这个function不熟悉，所以也许我用错了：

brachquest2 <- case_when(
  brachquest2$rasnaam %in% small_dogs ~ brachquest2[!(brachquest2$age_month < 11), ],
  brachquest2$rasnaam %in% medium_dogs ~ brachquest2[!(brachquest2$age_month < 13), ]
  )

然后我得到一个错误：长度必须为 66 或 1，而不是 18。

（行数为66）

我希望我解释得很好。 有人对我有一些有用的提示吗？ 或者它可能会更简单，感谢每一个帮助！ 提前致谢

下面是对 neilfws 的反应，只有 age_month 和 rasnaam 的 dput。 我不确定这是否是正确的方法

structure(list(age_month = structure(c(50, 52, 52.1, 49.7, 49.7, 
49.6, 49.6, 49.6, 49.5, 50, 48.8, 52.1, 51.9, 48.7, 50, 50.2, 
50.4, 50.5, 49, 49, 49, 49, 49, 48.9, 15, 17.6, 17.6, 17.6, 17.6, 
16.3, 17.6, 17.6, 15, 15.8, 16, 16.2, 17.5, 14.9, 10.4, 10.2, 
10.5, 10.4, 10.3, 10.3, 10.2, 10.3, 10.3, 10.3, 12.8, 12.8, 12.8, 
12.8, 12.8, 10, 10.4, 10.2, 10.3, 10.3, 12.7, 12.7, 13.2, 13.2, 
13.1, 13.1, 12.7, 12.7), units = "days", class = "difftime"), 
    rasnaam = c("American Staffordshire Terrier", "Boxer", "Bull Terrier", 
    "Chihuahua, langhaar", "Chihuahua, langhaar", "Chihuahua, langhaar", 
    "Chihuahua, langhaar", "Chihuahua, langhaar", "Chihuahua, langhaar", 
    "Chihuahua, langhaar", "Franse Bulldog", "Franse Bulldog", 
    "Labrador Retriever", "Shih Tzu", "American Staffordshire Terrier", 
    "American Staffordshire Terrier", "American Staffordshire Terrier", 
    "American Staffordshire Terrier", "American Staffordshire Terrier", 
    "American Staffordshire Terrier", "American Staffordshire Terrier", 
    "American Staffordshire Terrier", "American Staffordshire Terrier", 
    "American Staffordshire Terrier", "American Staffordshire Terrier", 
    "Boxer", "Boxer", "Boxer", "Boxer", "Boxer", "Bull Terrier", 
    "Bull Terrier", "Chihuahua, langhaar", "Chihuahua, langhaar", 
    "Chihuahua, langhaar", "Chihuahua, langhaar", "Chihuahua, langhaar", 
    "Franse Bulldog", "Franse Bulldog", "Franse Bulldog", "Franse Bulldog", 
    "Franse Bulldog", "Labrador Retriever", "Labrador Retriever", 
    "Labrador Retriever", "Labrador Retriever", "Labrador Retriever", 
    "Labrador Retriever", "Labrador Retriever", "Labrador Retriever", 
    "Labrador Retriever", "Labrador Retriever", "Labrador Retriever", 
    "Shih Tzu", "Shih Tzu", "Shih Tzu", "Shih Tzu", "Shih Tzu", 
    "American Staffordshire Terrier", "Boxer", "Franse Bulldog", 
    "Franse Bulldog", "Shih Tzu", "Shih Tzu", "American Staffordshire Terrier", 
    "Boxer")), row.names = c(NA, -66L), class = "data.frame")

Answer 1

如果您想坚持使用case_when ，这是实现您正在寻找的一种方法：

library(dplyr)

brachquest2 %>%
  mutate(
    # Create a temp var, removal_status, to label what rows should be kept or removed
    removal_status = case_when(
      (rasnaam %in% small_dogs) & age_month < 9 ~ "Remove",
      (rasnaam %in% medium_dogs) & age_month < 13 ~ "Remove",
      (rasnaam %in% large_dogs) & age_month < 24 ~ "Remove",
      TRUE ~ "Keep"
    )) %>% 
  # Keep only what's labelled "Keep"
  filter(removal_status == "Keep") %>% 
  # Remove temp var
  select(-removal_status)

使用您提供的small_dogs列表并创建我自己的medium_dogs列表，其中只有一个值，boxer，我得到以下结果（删除了 13 岁以下的 2 个拳击手）：

#   age_month                        rasnaam
# 1  50.0 days American Staffordshire Terrier
# 2  52.0 days                          Boxer
# 3  52.1 days                   Bull Terrier
# 4  49.7 days            Chihuahua, langhaar
# 5  49.7 days            Chihuahua, langhaar
# 6  49.6 days            Chihuahua, langhaar
# 7  49.6 days            Chihuahua, langhaar
# 8  49.6 days            Chihuahua, langhaar
# 9  49.5 days            Chihuahua, langhaar
# 10 50.0 days            Chihuahua, langhaar
# 11 48.8 days                 Franse Bulldog
# 12 52.1 days                 Franse Bulldog
# 13 51.9 days             Labrador Retriever
# 14 48.7 days                       Shih Tzu
# 15 50.0 days American Staffordshire Terrier
# 16 50.2 days American Staffordshire Terrier
# 17 50.4 days American Staffordshire Terrier
# 18 50.5 days American Staffordshire Terrier
# 19 49.0 days American Staffordshire Terrier
# 20 49.0 days American Staffordshire Terrier
# 21 49.0 days American Staffordshire Terrier
# 22 49.0 days American Staffordshire Terrier
# 23 49.0 days American Staffordshire Terrier
# 24 48.9 days American Staffordshire Terrier
# 25 15.0 days American Staffordshire Terrier
# 26 17.6 days                          Boxer
# 27 17.6 days                          Boxer
# 28 17.6 days                          Boxer
# 29 17.6 days                          Boxer
# 30 16.3 days                          Boxer
# 31 17.6 days                   Bull Terrier
# 32 17.6 days                   Bull Terrier
# 33 15.0 days            Chihuahua, langhaar
# 34 15.8 days            Chihuahua, langhaar
# 35 16.0 days            Chihuahua, langhaar
# 36 16.2 days            Chihuahua, langhaar
# 37 17.5 days            Chihuahua, langhaar
# 38 14.9 days                 Franse Bulldog
# 39 10.4 days                 Franse Bulldog
# 40 10.2 days                 Franse Bulldog
# 41 10.5 days                 Franse Bulldog
# 42 10.4 days                 Franse Bulldog
# 43 10.3 days             Labrador Retriever
# 44 10.3 days             Labrador Retriever
# 45 10.2 days             Labrador Retriever
# 46 10.3 days             Labrador Retriever
# 47 10.3 days             Labrador Retriever
# 48 10.3 days             Labrador Retriever
# 49 12.8 days             Labrador Retriever
# 50 12.8 days             Labrador Retriever
# 51 12.8 days             Labrador Retriever
# 52 12.8 days             Labrador Retriever
# 53 12.8 days             Labrador Retriever
# 54 10.0 days                       Shih Tzu
# 55 10.4 days                       Shih Tzu
# 56 10.2 days                       Shih Tzu
# 57 10.3 days                       Shih Tzu
# 58 10.3 days                       Shih Tzu
# 59 12.7 days American Staffordshire Terrier
# 60 13.2 days                 Franse Bulldog
# 61 13.2 days                 Franse Bulldog
# 62 13.1 days                       Shih Tzu
# 63 13.1 days                       Shih Tzu
# 64 12.7 days American Staffordshire Terrier

根据需要调整列表和 age_month 条件。