努力在 r 中取消嵌套 tibble（包括输入、代码和错误）

Question

我正在尝试取消嵌套物种计数 tibble，以便将其转换为数据框。最后四列是物种计数，目前为 'list' 形式（似乎是嵌套的？）。我希望这最后四个物种列的每一列和每一行都包含一个计数值 'int'（不包含 NULL，但在样带上未发现物种的情况下为 0）

我申请了：

        'df %>% unnest(c(cols))'

并收到此错误：

Error in `fn()`:
! In row 1, can't recycle input of size 4 to size 9.

这里是 dput() 形式的数据集的一个大大缩短的版本！感谢任何能提供帮助的人！

structure(list(Year = c(2019L, 2019L, 2019L, 2019L), Location = c("Tela", 
"Tela", "Tela", "Tela"), Site = c("AD", "AD", "AD", "AD"), Depth = c(10L, 
10L, 10L, 10L), Transect = 1:4, ID = c("2019_Tela_AD_1_10", "2019_Tela_AD_2_10", 
"2019_Tela_AD_3_10", "2019_Tela_AD_4_10"), `Stegastes planifrons` = list(
"1", NULL, NULL, c("10", "10", "10", "10", "10", "10", "10", 
"10", "10", "10")), `Anisotremus virginicus` = list(c("4", 
"4", "4", "4"), "1", NULL, NULL), `Stegastes adustus` = list(
c("9", "9", "9", "9", "9", "9", "9", "9", "9"), c("10", "10", 
"10", "10", "10", "10", "10", "10", "10", "10"), c("15", 
"15", "15", "15", "15", "15", "15", "15", "15", "15", "15", 
"15", "15", "15", "15"), c("14", "14", "14", "14", "14", 
"14", "14", "14", "14", "14", "14", "14", "14", "14")), `Stegastes partitus` = list(
c("9", "9", "9", "9", "9", "9", "9", "9", "9"), "1", c("14", 
"14", "14", "14", "14", "14", "14", "14", "14", "14", "14", 
"14", "14", "14"), c("10", "10", "10", "10", "10", "10", 
"10", "10", "10", "10"))), row.names = c(NA, -4L), class = c("tbl_df", 
"tbl", "data.frame"))

Answer 1

可能有更好的方法，但也许这对您有帮助：

library(purrr)
library(dplyr)

list_df <- df%>% 
  select(`Stegastes planifrons`, `Anisotremus virginicus`, `Stegastes adustus`, 
         `Stegastes partitus`) %>% 
  map_depth(., 2, ~ifelse(is.null(.x), 0, .x)) %>% 
  map_df(unlist) %>% 
  mutate_if(is.character, as.numeric)

df %>% 
  select(Year:ID) %>% 
  cbind(list_df)

Answer 2

您可以为此使用 apply：


cols_count <- colnames(tibble)[7:10] # select relevant cols

#Overwrite relevant parts of the dataframe
tibble[cols_count] <- apply(tibble[cols_count],
                            c(1,2), # go into every cell 
                            function(x) length(# get length of
                              unlist(x, recursive = FALSE) # a tibble cell is 
                              # a list itself, therefore unlist first
                            )
)# Apply function over relevant cells

这导致：

> tibble
# A tibble: 4 x 10
   Year Location Site  Depth Transect ID                `Stegastes planifrons` `Anisotremus virginicus` `Stegastes adustus` `Stegastes partitus`
  <int> <chr>    <chr> <int>    <int> <chr>                              <int>                    <int>               <int>                <int>
1  2019 Tela     AD       10        1 2019_Tela_AD_1_10                      1                        4                   9                    9
2  2019 Tela     AD       10        2 2019_Tela_AD_2_10                      0                        1                  10                    1
3  2019 Tela     AD       10        3 2019_Tela_AD_3_10                      0                        0                  15                   14
4  2019 Tela     AD       10        4 2019_Tela_AD_4_10                     10                        0                  14                   10

努力在 r 中取消嵌套 tibble（包括输入、代码和错误）

Struggling to unnest tibble (dput, code, and error included) in r

r

tidyr

tibble

unnest

dput