创建从 0 到 table 变量值的新列

Creating new columns that go from 0 to the value in the variable of a table

可重现的小标题: 我有一个类似于下图所示的数据库。不同之处在于我正在使用的数据库要大得多。

general_tibble <- tibble(gender = c("female", "female", "male"),
                             age = c(18, 19,18),
                             age_partner = c(22,20,17),
                             max_age = c(60, 60, 65), 
                             nrs =c(42,41,47))

general_tibble 结果:

  gender age age_partner max_age nrs
1 female  18          22      60  42
2 female  19          20      60  41
3   male  18          17      65  47

问题: 我如何从以前的 table 创建一个新的 table,它采用 nrs 的值,并创建一个名为 n 的列变量,从 0 到nrs?

中的值

为了进一步说明,在 general_tibble 的第 1 行中,列 nrs 等于 42,因此该列将从 0 变为 42,在第 2 行中 nrs 等于41 所以列将从 0 到 41,第 3 行也是如此。

我目前正在使用下面的代码。它可以工作,但是当 general_tibble 太大时,代码执行起来非常慢。

general_list <- list()

for(i in 1:NROW(general_tibble)){
  general_list[[i]] <- data.frame(general_tibble[i, ], 
                             n = 0:general_tibble[[i, "nrs"]])
} 

然后我bind_rows()general_list得到general_binded

general_binded <- bind_rows(general_list)

general_binded[c(1:5, 38:42),] 结果:

   gender age age_partner max_age nrs  n
1  female  18          22      60  42  0
2  female  18          22      60  42  1
3  female  18          22      60  42  2
4  female  18          22      60  42  3
5  female  18          22      60  42  4
38 female  18          22      60  42 37
39 female  18          22      60  42 38
40 female  18          22      60  42 39
41 female  18          22      60  42 40
42 female  18          22      60  42 41

PS: 在 for 循环中我使用 data.frame() 而不是 tibble() 因为我想回收行。如果您有一些涉及小标题或数据框的建议,我很乐意采纳。

我们可以用uncount

library(tidyverse)
general_tibble %>% 
   mutate(grp = row_number(), nrsN = nrs + 1) %>% 
   uncount(nrsN) %>%
   group_by(grp) %>% 
   mutate(n = row_number() - 1) %>%
   ungroup %>%
   select(-grp)
# A tibble: 133 x 6
#   gender   age age_partner max_age   nrs     n
#   <chr>  <dbl>       <dbl>   <dbl> <dbl> <dbl>
# 1 female    18          22      60    42     0
# 2 female    18          22      60    42     1
# 3 female    18          22      60    42     2
# 4 female    18          22      60    42     3
# 5 female    18          22      60    42     4
# 6 female    18          22      60    42     5
# 7 female    18          22      60    42     6
# 8 female    18          22      60    42     7
# 9 female    18          22      60    42     8
#10 female    18          22      60    42     9
# … with 123 more rows

另一种选择是unnest

general_tibble %>% 
   mutate(n = map(nrs+1, ~  seq(.x) - 1)) %>%
   unnest

一种使用基础 R 的方法(减去 tibble 包)。

首先,按nrs组划分。其次,通过 nrs 值扩展每个数据框的行。第三,创建代表 0:whatever 行数的 id 列。四、带回一个tibble:

library(tibble)

df <- tibble(
  gender      = c("female", "female", "male"),
  age         = c(18, 19, 18),
  age_partner = c(22, 20, 17),
  max_age     = c(60, 60, 65), 
  nrs         = c(42, 41, 47)
  )

nrs_split <- split(df, df$nrs)
df_list <- lapply(nrs_split, function(i) i[rep(seq_len(nrow(i)), each=i$nrs + 1), ])
df_renum <- lapply(df_list, function(i) {i$id <- 0:rle(i$nrs)$values; return(i)})
df <- do.call("rbind", df_renum)
df
#> # A tibble: 133 x 6
#>    gender   age age_partner max_age   nrs    id
#>  * <chr>  <dbl>       <dbl>   <dbl> <dbl> <int>
#>  1 female    19          20      60    41     0
#>  2 female    19          20      60    41     1
#>  3 female    19          20      60    41     2
#>  4 female    19          20      60    41     3
#>  5 female    19          20      60    41     4
#>  6 female    19          20      60    41     5
#>  7 female    19          20      60    41     6
#>  8 female    19          20      60    41     7
#>  9 female    19          20      60    41     8
#> 10 female    19          20      60    41     9
#> # … with 123 more rows

最简单的方法是使用 tidyr::expand() 函数扩展 nrs 列上的 general_tibble

library(tidyverse)

general_tibble %>% 
        group_by_all()%>% 
        expand(n = 0:nrs)

#> # A tibble: 133 x 6
#> # Groups:   gender, age, age_partner, max_age, nrs [3]
#>    gender   age age_partner max_age   nrs     n
#>    <chr>  <dbl>       <dbl>   <dbl> <dbl> <int>
#>  1 female    18          22      60    42     0
#>  2 female    18          22      60    42     1
#>  3 female    18          22      60    42     2
#>  4 female    18          22      60    42     3
#>  5 female    18          22      60    42     4
#>  6 female    18          22      60    42     5
#>  7 female    18          22      60    42     6
#>  8 female    18          22      60    42     7
#>  9 female    18          22      60    42     8
#> 10 female    18          22      60    42     9
#> # ... with 123 more rows

reprex package (v0.2.1)

创建于 2019-05-21

仅使用 base R 函数的另一个想法:

expanded_vars <- do.call(rbind,lapply(general_tibble$nrs, 
                                              function(x) expand.grid(x, 0:x)))
names(expanded_vars) <- c("nrs", "n")

merge(y = expanded_vars, x = general_tibble, by = "nrs", all = TRUE)

使用dplyrtidyr,您还可以:

general_tibble %>%
 group_by(rowid = row_number()) %>%
 mutate(n = nrs) %>%
 complete(n = seq(0, n, 1)) %>%
 fill(everything(), .direction = "up") %>%
 ungroup() %>%
 select(-rowid)

       n gender   age age_partner max_age   nrs
   <dbl> <chr>  <dbl>       <dbl>   <dbl> <dbl>
 1     0 female    18          22      60    42
 2     1 female    18          22      60    42
 3     2 female    18          22      60    42
 4     3 female    18          22      60    42
 5     4 female    18          22      60    42
 6     5 female    18          22      60    42
 7     6 female    18          22      60    42
 8     7 female    18          22      60    42
 9     8 female    18          22      60    42
10     9 female    18          22      60    42

使用 data.tabletidyverse 的一个好处是,您无需根据您正在做的事情是否是 mutateexpand,或 summarize。您可以将您想要的内容放入 df[i, j, k]j 部分,无论解析为多少行,这就是您得到的内容。

library(data.table)
setDT(general_tibble)

general_tibble[, .(n = seq(0, nrs))
               , by = names(general_tibble)]


#      gender age age_partner max_age nrs  n
#   1: female  18          22      60  42  0
#   2: female  18          22      60  42  1
#   3: female  18          22      60  42  2
#   4: female  18          22      60  42  3
#   5: female  18          22      60  42  4
#  ---                                      
# 129:   male  18          17      65  47 43
# 130:   male  18          17      65  47 44
# 131:   male  18          17      65  47 45
# 132:   male  18          17      65  47 46
# 133:   male  18          17      65  47 47