R-根据特定组计算特定数字的连续出现次数

Question

在R中说我有数据帧：

frame object  positive     
1     6       0    
2     6       1    
3     6       1    
4     6       1    
5     6       1      
6     6       0    
7     6       0    
8     6       1 
9     6       1   
10    6       1
1     7       1    
2     7       1   
3     7       1    
4     7       1   
5     7       1      
6     7       0    
7     7       1       
8     7       0    
9     7       1    
10    7       1

我正在尝试创建一个新的表，该表统计每个单独对象的正列中值为1的连续出现次数，并输出最大和平均连续出现次数。看起来像：

object  max  mean 
6       4    3.5
7       5    8/3

谢谢你的帮助！

Answer 1

这里有一个使用data.table::rleid查找连续出现的1s的解决方案。

library("tidyverse")
df <- tibble::tribble(
~frame, ~object, ~positive,
1L, 6L, 0L,
2L, 6L, 1L,
3L, 6L, 1L,
4L, 6L, 1L,
5L, 6L, 1L,
6L, 6L, 0L,
7L, 6L, 0L,
8L, 6L, 1L,
9L, 6L, 1L,
10L, 6L, 1L,
1L, 7L, 1L,
2L, 7L, 1L,
3L, 7L, 1L,
4L, 7L, 1L,
5L, 7L, 1L,
6L, 7L, 0L,
7L, 7L, 1L,
8L, 7L, 0L,
9L, 7L, 1L,
10L, 7L, 1L
)

df %>%
group_by(object) %>%
mutate(
sequence = data.table::rleid(positive == 1),
) %>%
filter(
positive == 1
) %>%
group_by(
object, sequence
) %>%
summarise(
length = n()
) %>%
summarise(
max = max(length),
mean = mean(length)
)
#> `summarise()` has grouped output by 'object'. You can override using the
#> `.groups` argument.
#> # A tibble: 2 × 3
#>   object   max  mean
#>    <int> <int> <dbl>
#> 1      6     4  3.5 
#> 2      7     5  2.67

^{创建于2022-07-26由reprex包(v2.0.1(}

Answer 2

我创建了自己的数据，所以输出不会完全是您显示的那样。尽管如此，它还是应该奏效。

library(dplyr)
sat.seed(111)
df <- data.frame(frame=c(1:10,1:10),
object=rep(6:7, each=10),
positive=sample(0:1,20, replace=T))
df
frame object positive
1      1      6        1
2      2      6        1
3      3      6        1
4      4      6        0
5      5      6        1
6      6      6        0
7      7      6        0
8      8      6        0
9      9      6        1
10    10      6        1
11     1      7        1
12     2      7        0
13     3      7        1
14     4      7        0
15     5      7        0
16     6      7        1
17     7      7        0
18     8      7        0
19     9      7        0
20    10      7        1    
df %>% group_by(object) %>%  summarise(mean=mean(rle(positive)$lengths[rle(positive)$values==1]) ,
max=max(rle(positive)$lengths[rle(positive)$values==1]))
# A tibble: 2 × 3
object  mean   max
<int> <dbl> <int>
1      6     2     3
2      7     1     1