获得各组dplyr的相对丰度

我有以下几点：

 dd <- structure(list(group_members = structure(c(6L, 6L, 1L, 1L, 2L, 2L, 3L, 3L, 4L, 4L, 5L, 5L),
 .Label = c("1", "2", "3", "4", "5", ">6"), class = "factor"), Test_A = c("negative", "positive",
 "negatiu", "positive", "negatiu", "positive", "negatiu", "positive", "negatiu", "positive", "negatiu", "positive"), cases = c(58L, 2L, 14781L, 3525L, 7867L, 415L, 4113L, 72L, 2054L, 10L, 347L, 2L)), row.names = c(NA, -12L), groups = structure(list(group_members = structure(1:6, .Label = c("1", "2", "3", "4", "5", ">6"), class = "factor"), .rows = structure(list( 3:4, 5:6, 7:8, 9:10, 11:12, 1:2), ptype = integer(0), class = c("vctrs_list_of", "vctrs_vctr", "list"))), row.names = c(NA, 6L), class = c("tbl_df", "tbl", "data.frame"), .drop = TRUE), class = c("grouped_df", "tbl_df", "tbl", "data.frame"))

dd
#一个tibble:12x3
#组别：组别成员[6]
组成员测试A案例
1>6负58
2>6正2
3 1否定14781
4 1正3525
5 2否定7867
6 2正415
7 3否定4113
8 3阳性72
9 4否定号2054
10 4正10
11 5否定347
12 5正2

我想知道每个群体的相对丰度。例如“组成员>6”我有58例阴性病例和2例阳性病例。我想得到一个新的专栏如下：

例如，第6组：“频率=58/60=0.96和“频率=2/60=0.04”

>dd
#一个tibble:12x3
#组别：组别成员[6]
小组成员测试案例频率
1>6负58 0.96
2>6正2 0.004
.....

谢谢你的帮助

dd %>%
  group_by(group_members) %>%
  mutate(frequency = cases / sum(cases))

给出：

# A tibble: 12 x 4
# Groups:   group_members [6]
   group_members Test_A   cases frequency
   <fct>         <chr>    <int>     <dbl>
 1 >6            negative    58   0.967  
 2 >6            positive     2   0.0333 
 3 1             negatiu  14781   0.807  
 4 1             positive  3525   0.193  
 5 2             negatiu   7867   0.950  
 6 2             positive   415   0.0501 
 7 3             negatiu   4113   0.983  
 8 3             positive    72   0.0172 
 9 4             negatiu   2054   0.995  
10 4             positive    10   0.00484
11 5             negatiu    347   0.994  
12 5             positive     2   0.00573

#一个tible:12 x 4
#组别：组别成员[6]
小组成员测试案例频率
1>6负58 0.967
2>6正2 0.0333
3 1否定14781 0.807
4 1正3525 0.193
5.2否定7867 0.950
6 2正极415 0.0501
7 3否定4113 0.983
8 3正72 0.0172
9 4否定2054 0.995
10 4正10 0.00484
11 5否定347 0.994
12 5正2 0.00573

给出：

# A tibble: 12 x 4
# Groups:   group_members [6]
   group_members Test_A   cases frequency
   <fct>         <chr>    <int>     <dbl>
 1 >6            negative    58   0.967  
 2 >6            positive     2   0.0333 
 3 1             negatiu  14781   0.807  
 4 1             positive  3525   0.193  
 5 2             negatiu   7867   0.950  
 6 2             positive   415   0.0501 
 7 3             negatiu   4113   0.983  
 8 3             positive    72   0.0172 
 9 4             negatiu   2054   0.995  
10 4             positive    10   0.00484
11 5             negatiu    347   0.994  
12 5             positive     2   0.00573

#一个tible:12 x 4
#组别：组别成员[6]
小组成员测试案例频率
1>6负58 0.967
2>6正2 0.0333
3 1否定14781 0.807
4 1正3525 0.193
5.2否定7867 0.950
6 2正极415 0.0501
7 3否定4113 0.983
8 3正72 0.0172
9 4否定2054 0.995
10 4正10 0.00484
11 5否定347 0.994
12 5正2 0.00573

# A tibble: 12 x 4
# Groups:   group_members [6]
   group_members Test_A   cases frequency
   <fct>         <chr>    <int>     <dbl>
 1 >6            negative    58   0.967  
 2 >6            positive     2   0.0333 
 3 1             negatiu  14781   0.807  
 4 1             positive  3525   0.193  
 5 2             negatiu   7867   0.950  
 6 2             positive   415   0.0501 
 7 3             negatiu   4113   0.983  
 8 3             positive    72   0.0172 
 9 4             negatiu   2054   0.995  
10 4             positive    10   0.00484
11 5             negatiu    347   0.994  
12 5             positive     2   0.00573