tidyr

本文介绍了tidyr - 获得组合的独特方式(仅使用 tidyverse)的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我想使用 tidyverse(理想情况下)获取数据帧的唯一字符串列的所有唯一成对组合.

I wanted to get all unique pairwise combinations of a unique string column of a dataframe using the tidyverse (ideally).

这是一个虚拟示例:

library(tidyverse) a <- letters[1:3] %>% tibble::as_tibble() a #> # A tibble: 3 x 1 #> value #> <chr> #> 1 a #> 2 b #> 3 c tidyr::crossing(a, a) %>% magrittr::set_colnames(c("words1", "words2")) #> # A tibble: 9 x 2 #> words1 words2 #> <chr> <chr> #> 1 a a #> 2 a b #> 3 a c #> 4 b a #> 5 b b #> 6 b c #> 7 c a #> 8 c b #> 9 c c

有没有办法在这里删除重复"组合.在这个例子中，输出如下:

Is there a way to remove 'duplicate' combinations here. That is have the output be the following in this example:

# A tibble: 9 x 2 #> words1 words2 #> <chr> <chr> #> 1 a b #> 2 a c #> 3 b c

我希望有一个很好的 purrr::map 或 filter 方法来完成上述操作.

I was hoping there would be a nice purrr::map or filter approach to pipe into to complete the above.

有与此类似的问题，例如此处，由@Sotos 标记.在这里，我专门寻找 tidyverse (purrr, dplyr) 方法来完成我设置的管道.其他答案使用了我不想作为依赖项包含在内的各种其他包.

There are similar questions to this one e.g. here, marked by @Sotos. Here I am specifically looking for tidyverse (purrr, dplyr) ways to complete the pipeline I have setup. The other answers use various other packages that I do not want to include as dependencies.

推荐答案

希望有更好的方法，但我通常使用这个...

wish there was a better way, but I usually use this...

library(tidyverse) df <- tibble(value = letters[1:3]) df %>% expand(value, value1 = value) %>% filter(value < value1) # # A tibble: 3 x 2 # value value1 # <chr> <chr> # 1 a b # 2 a c # 3 b c