在 R 中将两行合二为一

Question

我遇到了另一个挑战，即根据标识符 col 将两行合并为一行。

我的数据集如下所示：

var<-c("round","round","round","hhid","hhid","chid","chid","sex")
dfile<-c("df1","df2","df3","df1","df2","df1","df2","df1")
uniquevar<-c("df1::round","df2::round","df3::round", "df1::hhid","df2::hhid","df1::chid","df2::chid","df1::sex")
flag<-c("dup","dup","dup","dup","dup","dup","dup","NA")
df<-data.frame(var, dfile,flag)

我正在尝试做

1. 找到标记为“dup”的obs
2. 如果它被标记为“dup”，将两行/三行/或多行合并为一个格式：df1::var | df2::var |df3::var

所以，理想的结果应该是这样的

var      dfile.                    uniquevar                               flag
round    df1 |df2 |df3             df1::round | df2::round |df3::round      dup
hhid     df1 |df2                  df1::hhid | df2::hhid                    dup
chid     df1 |df2                  df1::chid | df2::chid                    dup
sex      df1                                                                NA

目前只能在excel中手动操作，实在是太费时间了。 如果我能被告知如何在 R 中实现这一目标，我将不胜感激，考虑到数据集包含超过 600,000 个 obs，这会更快......

非常感谢~~！

Answer 1

您可以在使用group_by(var)后将单元格paste在一起。 使用sep = "::"指定不同列之间的分隔符，使用collapse = " | "表示行的分隔符。 您可以在dplyr package 的summarize中执行此操作。

library(dplyr)

df %>%
  group_by(var) %>%
  summarize(uniquevar = ifelse(all(flag == "dup"),
                               paste(dfile, var, sep = "::", collapse = " | "),
                               ""),
            dfile = paste(dfile, collapse = " | "),
            dup = flag[1]) %>%
  select(var, dfile, uniquevar, dup)
#> # A tibble: 4 x 4
#>  var   dfile           uniquevar                              dup  
#>   <chr> <chr>           <chr>                                  <chr>
#> 1 chid  df1 | df2       "df1::chid | df2::chid"                dup  
#> 2 hhid  df1 | df2       "df1::hhid | df2::hhid"                dup  
#> 3 round df1 | df2 | df3 "df1::round | df2::round | df3::round" dup  
#> 4 sex   df1             ""                                     NA