r - 根据组的特定成员过滤组的所有行

Question

<分区>

Answer 1

适应How to filter (with dplyr) for all values of a group if variable limit is reached?

我们得到:

x %>%
    group_by(ID) %>%
    filter(any(Metric[Hour == '2'] <= 5))

# # A tibble: 7 x 3
# # Groups:   ID [2]
# ID   Hour Metric
# <fctr> <fctr>  <dbl>
#     1      A      0      3
# 2      A      2      4
# 3      A      5      1
# 4      A      6      6
# 5      A      9      7
# 6      C      0      1
# 7      C      2      1

这些类型的问题也可以通过首先创建一个按组的中间变量来解决，以标记是否应删除行。

方法一:

x %>%
    group_by(ID) %>%
    mutate(keep_group = (any(Metric[Hour == '2'] <= 5))) %>%
    ungroup %>%
    filter(keep_group) %>%
    select(-keep_group)

方法二:

groups_to_keep <-
    x %>%
    filter(Hour == '2', Metric <= 5) %>%
    select(ID) %>%
    distinct() # N.B. this sorts groups_to_keep by ID which may not be desired
#    ID
# 1  A
# 2  C

x %>%
    inner_join(groups_to_keep, by = 'ID')
#    ID Hour Metric
# 1  A    0      3
# 2  A    2      4
# 3  A    5      1
# 4  A    6      6
# 5  A    9      7
# 6  C    0      1
# 7  C    2      1

方法 3 - 正如@thelatemail 所建议的(对于重复 ID 是安全的):

groups_not_to_keep <-
    x %>% 
    filter(Hour == 2, Metric > 5) %>% 
    select(ID)

x %>%
    anti_join(groups_not_to_keep, by = 'ID')