在數據框中的多列中計數“1”

Question

給定以下數據框：

fruit <- c("Orange", "Apple", "Apple", "Orange", "Banana", "Orange", "Banana", "Pear", "Banana", "Pear", "Pear", "Apple")
col2 <- c("0", "0", "1", "0", "0", "0", "1", "0", "0", "0", "0", "1")
col3 <- c("1", "1", "0", "0", "0", "1", "1", "0", "0", "0", "0", "0")
col4 <- c("0", "1", "0", "1", "1", "1", "0", "0", "0", "1", "1", "0")
df <- data.frame(fruit, col2, col3, col4)

    fruit col2 col3 col4
1  Orange    0    1    0
2   Apple    0    1    1
3   Apple    1    0    0
4  Orange    0    0    1
5  Banana    0    0    1
6  Orange    0    1    1
7  Banana    1    1    0
8    Pear    0    0    0
9  Banana    0    0    0
10   Pear    0    0    1
11   Pear    0    0    1
12  Apple    1    0    0

我想計算每列中“1”的頻率並將它們顯示在表格中，如下所示：

    fruit col2 col3 col4
1  Orange   0    2    2
2  Apple    2    1    1
3  Banana   1    1    1
4  Pear     0    0    1

我嘗試使用dplyr來獲得結果，但無法在多個列中完成。 這是我使用的代碼：

df %>%
  group_by(fruit) %>%
  summarise(Count = n()) %>%
  group_by_all %>%
  spread(fruit, Count, fill = 0)

我是 R 的初學者，有人可以幫忙嗎？

Answer 1

我們可以across按'fruit'分組后使用summarise with cross遍歷列並獲得邏輯向量的sum

library(dplyr)
df %>%
   group_by(fruit) %>% 
   summarise(across(everything(), ~ sum(. == '1')))

-輸出

# A tibble: 4 x 4
#  fruit   col2  col3  col4
#* <chr>  <int> <int> <int>
#1 Apple      2     1     1
#2 Banana     1     1     1
#3 Orange     0     2     2
#4 Pear       0     0     2

Answer 2

使用基礎 R aggregate ：

aggregate(.~fruit, df, function(x) sum(x == '1'))

#   fruit col2 col3 col4
#1  Apple    2    1    1
#2 Banana    1    1    1
#3 Orange    0    2    2
#4   Pear    0    0    2