R：将行转换为具有 NA 条目的列（使用 tidyr 时出错：spread）

Question

我有以下数据集

Pet Shop	Item	Price
A	dog	300
A	fish	20
A	turtle	50
A	dog	250
A	cat	280
A	rabbit	180
A	cat	270
B	dog	350
B	fish	70
B	cat	220
B	turtle	80
B	fish	55
B	fish	75
C	dog	280
C	cat	260
C	fish	65

数据的代码如下

Pet_Shop = c(rep("A",7), rep("B",6), rep("C",3))
Item = c("Dog","Fish","Turtle","Dog","Cat","Rabbit","Cat","Dog","Fish","Cat","Turtle","Fish","Fish","Dog","Cat","Fish")
Price = c(300,20,50,250,280,180,270,350,70,220,80,55,75,280,260,65)
Data = data.frame(Pet_Shop, Item, Price)

我正在尝试将数据更改为以下内容table

有人知道怎么做吗？我尝试使用 spread 执行以下方法，但它 returns 一个错误

Test = spread(Data, Item, Price)

Error: Each row of output must be identified by a unique combination of keys.
Keys are shared for 7 rows:
* 5, 7
* 1, 4
* 9, 12, 13

谢谢！

Answer 1

这应该能找到您要找的东西。注意 pivot_wider 和 pivot_longer 分别是 spread 和 gather 的新 dplyr 版本。问题是您需要在转换之前为每个名称创建一个唯一标识符行。

new_data <- Data %>%
  mutate(row = row_number()) %>%
  pivot_wider(names_from = Item, values_from = Price) %>%
  select(-row)

输出：

   Pet_Shop   Dog  Fish Turtle   Cat Rabbit
   <chr>    <dbl> <dbl>  <dbl> <dbl>  <dbl>
 1 A          300    NA     NA    NA     NA
 2 A           NA    20     NA    NA     NA
 3 A           NA    NA     50    NA     NA
 4 A          250    NA     NA    NA     NA
 5 A           NA    NA     NA   280     NA
 6 A           NA    NA     NA    NA    180
 7 A           NA    NA     NA   270     NA
 8 B          350    NA     NA    NA     NA
 9 B           NA    70     NA    NA     NA
10 B           NA    NA     NA   220     NA
11 B           NA    NA     80    NA     NA
12 B           NA    55     NA    NA     NA
13 B           NA    75     NA    NA     NA
14 C          280    NA     NA    NA     NA
15 C           NA    NA     NA   260     NA
16 C           NA    65     NA    NA     NA

R：将行转换为具有 NA 条目的列（使用 tidyr 时出错：spread）

R: Turning row into columns with NA entries (error using tidyr: spread)

r

dataframe

pivot

reshape

melt