R:列集中的最后一个非NA值

Question

我正在寻找下面的问题的解决方案,将在管道中支持.

我的数据看起来像这样:

tibble(
  column_set_1_1 = c(1, 2, 3), column_set_1_2 = c(2, 3, NA), column_set_1_3 = c(3, NA, NA),
  column_set_2_1 = c(1, 2, 3), column_set_2_2 = c(4, 5, 6), column_set_2_3 = c(7, 8, 9), 
  column_set_2_4 = c(10, 11, NA), column_set_2_5 = c(13, NA, NA), column_set_2_6 = c(NA, NA, NA)
)

# A tibble: 3 × 9
  column_set_1_1 column_set_1_2 column_set_1_3 column_set_2_1 column_set_2_2 column_set_2_3 column_set_2_4 column_set_2_5 column_set_2_6
           <dbl>          <dbl>          <dbl>          <dbl>          <dbl>          <dbl>          <dbl>          <dbl>          <lgl>
1              1              2              3              1              4              7             10             13             NA
2              2              3             NA              2              5              8             11             NA             NA
3              3             NA             NA              3              6              9             NA             NA             NA

我基本上希望按列集获取最后一个非NA值.所以,预期的输出是:

tibble(
  column_set_1 = c(3, 3, 3), 
  column_set_2 = c(13, 11, 9)
)

# A tibble: 3 × 2
  column_set_1 column_set_2
         <dbl>        <dbl>
1            3           13
2            3           11
3            3            9

Answer 1

这是一种tidyverse不重新整形原始数据帧但通过列名模式将其拆分为组的方法,并使用coalesce函数获取每个子数据帧中的最后一个非NA值:

library(tidyverse)
df_foo %>% 
      mutate_all(as.numeric) %>% 
      split.default(f = sub("_\\d+$", "", names(.))) %>% 
      map_df(~do.call(coalesce, setNames(rev(.), NULL)))

# A tibble: 3 × 2
#  column_set_1 column_set_2
#         <dbl>        <dbl>
#1            3           13
#2            3           11
#3            3            9