如何汇总两列数据满足某conditions/criterion的numbers/populations（使用"dplyr"）？

Question

这是样本数据和测试结果：

tta <- data.frame(v1=c(8, 6, 1, 3, 8, 3, 3, 4, 5, 5, 7, 3, 4, 2, 8, 2, 2, 2, 5, 8, 4, 5, 3, 5, 3),
                  v2=c(9, 5, 3, 5, 4, 4, 8, 3, 1, 3, 3, 7, 7, 7, 9, 3, 7, 3, 3, 8, 4, 6, 3, 7, 5),
                  group=c(rep(c(1:5), each=5)))

## not perfect and need downstream analysis or merge
resulta <- tta %>%
    filter(v1<=6 & v2<=6) %>%
    group_by(group) %>%
    summarise(n=n(), frac=n/5)

## resulta
##     lost the group 3 that has no data meet the criterion that "v1<=6 & v2<=6"
## 
## # A tibble: 4 × 3
##   group     n  frac
##   <int> <int> <dbl>
## 1     1     3   0.6
## 2     2     4   0.8
## 3     4     3   0.6
## 4     5     4   0.8

## expect results
##
## # A tibble: 4 × 3
##   group     n  frac
##   <int> <int> <dbl>
## 1     1     3   0.6
## 2     2     4   0.8
## 3     3     0   0.0
## 4     4     3   0.6
## 5     5     4   0.8
##

有两个问题：

如果您先使用 filter，则丢失没有数据满足条件（“v1<=6 & v2<=6”）的第 3 组。
frac=n/5：分组数据不是5行或随机长度，人口计算不完善

有什么解决办法吗？除了 dplyr 之外的另一种方法也可以。感谢您的帮助

Answer 1

你可以试试，

tta %>%
  mutate(key = as.numeric(v1<=6 & v2<=6)) %>%
  group_by(group) %>%
  summarize(n = sum(key), frac = n/n())

  group     n  frac
  <int> <dbl> <dbl>
1     1     3   0.6
2     2     4   0.8
3     3     0   0  
4     4     3   0.6
5     5     4   0.8

如何汇总两列数据满足某conditions/criterion的numbers/populations（使用"dplyr"）？

How to summarize the numbers/populations that the data in two columns meet some conditions/criterion (by using "dplyr")?

r

dplyr