如何使用2个类别变量和1个数字变量的信息创建新变量

Question

我有一个数据集，看起来像这样：

ID  Meal    Food    Amount
1   Lunch   Meat    50
1   Lunch   Potato  10
1   Dinner  Fish    105
1   Dinner  Rice    100
1   Dinner  Pulses  50
2   BF     Cereal   100
2   BF      Milk    200
2   Lunch   Rice    200
2   Lunch   Chicken 150
2   Lunch   Veg     100
2   Dinner  Pasta   200
2   Dinner  Meat    200
2   Dinner  Tomato  50
2   Dinner  Cheese  10

我想使用变量Food，Meal和Amount中的信息来创建几个新变量，因此一行上只有一个ID。 因此，我将使用诸如Cereal_BF，Cereal_Lunch，Cereal_Dinner，Meat_BF，Meat_Lunch，Meat_Dinner，Potato_BF，Potato_Lunch，Potato_Dinner等变量，这些变量显示来自变量Amount的对应信息。

谢谢您的帮助！

帕特里夏

Answer 1

您可以合并列，并使用tidyverse函数传播它们。

dd %>% 
   unite(MealFood, Meal, Food) %>% 
   spread(MealFood, Amount)

哪里

dd<-read.table(text="ID  Meal    Food    Amount
1   Lunch   Meat    50
               1   Lunch   Potato  10
               1   Dinner  Fish    105
               1   Dinner  Rice    100
               1   Dinner  Pulses  50
               2   BF     Cereal   100
               2   BF      Milk    200
               2   Lunch   Rice    200
               2   Lunch   Chicken 150
               2   Lunch   Veg     100
               2   Dinner  Pasta   200
               2   Dinner  Meat    200
               2   Dinner  Tomato  50
               2   Dinner  Cheese  10", header=T, stringsAsFactors=F)