使用 pmap 函数检查一行中的所有值是正数还是负数 [英] Using pmap function to check whether all values in a row are positive or negative

问题描述

我有这个数据框，我想单独使用 pmap 函数来过滤所有值为负或正的行.我正在寻找一种简洁的方法来做到这一点，因为我想到了 c(...) 但我们只能在函数中使用它.可以通过以下代码实现:

I have this data frame and I would like to solely use pmap function to filter only rows where all values are either negative or positive. I am looking for a concise way of doing this as I thought about c(...) but we can only use it inside a function. It is achievable by this code:

df <- tibble(x = c("a", "b", "c"), y = c(1, -1, -1), z = c(1, -1, 1), 
             p = c(1, -1, -1))

df %>%
  filter(pmap_lgl(list(y, z, p), ~ ..1 > 0 & ..2 > 0 & ..3 > 0  | 
                    ..1 < 0 & ..2 < 0 & ..3 < 0))

# A tibble: 2 x 4
  x         y     z     p
  <chr> <dbl> <dbl> <dbl>
1 a         1     1     1
2 b        -1    -1    -1

所以我正在寻找一种将谓词应用于所有值的方法，以防我有超过 3 列我不想命名它们或像这样引用它们.

So I am looking for a way that predicate applies on all values in case I had more than 3 columns that I don't want to name them or refer to them like this.

任何帮助将不胜感激，并提前感谢您.

Any help would be highly appreciated and thank you in advance.

推荐答案

我们可以使用if_all

library(dplyr)
df %>% 
    filter(across(where(is.numeric), ~ . > 0)|
           if_all(where(is.numeric), ~ . < 0))

-输出

# A tibble: 2 x 4
#  x         y     z     p
#  <chr> <dbl> <dbl> <dbl>
#1 a         1     1     1
#2 b        -1    -1    -1

---

或者使用 pmap 通过 selecting numeric 列，检查 all 的值是否小于 0或 | 大于 0

---

Or with pmap by selecting the numeric columns, check whether all the values are less than 0 or | greater than 0

library(purrr)
df %>%
   filter(pmap_lgl(select(., where(is.numeric)), 
              ~ all(c(...) < 0)| all(c(...)> 0)))

-输出

# A tibble: 2 x 4
#  x         y     z     p
#  <chr> <dbl> <dbl> <dbl>
#1 a         1     1     1
#2 b        -1    -1    -1

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