R:根据其他列条件比较列中的元素？

Question

我想根据每个主题的第二个或第三个条件是否大于第一个条件来创建一个新的df。

示例 df:

df1 <- data.frame(subject = rep(1:5, 3),
                  condition = rep(c("first", "second", "third"), each = 5),
                  values = c(.4, .4, .4, .4, .4, .6, .6, .6, .6, .4, .6, .6, .6, .4, .4))
> df1
   subject condition values
1        1     first    0.4
2        2     first    0.4
3        3     first    0.4
4        4     first    0.4
5        5     first    0.4
6        1    second    0.6
7        2    second    0.6
8        3    second    0.6
9        4    second    0.6
10       5    second    0.4
11       1     third    0.6
12       2     third    0.6
13       3     third    0.6
14       4     third    0.4
15       5     third    0.4

生成的 df 将是这样的:

> df2
   subject condition values
1        1     first    0.4
2        2     first    0.4
3        3     first    0.4
4        4     first    0.4
6        1    second    0.6
7        2    second    0.6
8        3    second    0.6
9        4    second    0.6
11       1     third    0.6
12       2     third    0.6
13       3     third    0.6
14       4     third    0.4

此处，主题 #5 不符合标准。这是因为只有主题 #5 的值在第二个或第三个条件中不大于第一个条件。

谢谢。

Answer 1

如果第二个或第三个“值”中的任何一个大于“第一个”，我们可以按“主题”和过滤器进行分组

library(dplyr)
df1 %>% 
 group_by(subject) %>%
 filter(any(values[2:3] > first(values))) %>%
 ungroup

-输出

# A tibble: 12 × 3
   subject condition values
     <int> <chr>      <dbl>
 1       1 first        0.4
 2       2 first        0.4
 3       3 first        0.4
 4       4 first        0.4
 5       1 second       0.6
 6       2 second       0.6
 7       3 second       0.6
 8       4 second       0.6
 9       1 third        0.6
10       2 third        0.6
11       3 third        0.6
12       4 third        0.4