根据其他数据集的列名在新列中添加值

Question

Currently I have two datasets. One with locations within the company and the amount of products that are being produced at each location on each day. The other with the locations and the capacity of each location on each day. I have illustrated both of them below.

Dataset 1 (Amount of products product on certain days of the week):

Location	Day of the week	Produced
Location A	Monday	20
Location B	Monday	30
Location C	Monday	55
Location A	Tuesday	25
Location B	Tuesday	24
Location C	Tuesday	70

Dataset 2 (The capacity of each location on each day of the week)

Location	Monday	Tuesday
Location A	50	50
Location B	60	50
Location C	80	80

What I want to do is add a new column to the first dataset. I want that column to be named 'Capacity' and I want it to kinda look like this:

Location	Day of the week	Produced	Capacity
Location A	Monday	20	50
Location A	Tuesday	25	50

I've tried multiple ifelse statements, but failed miserably and are working on it for quite some time now. Is there someone who might know a fix?

Answer 1

You can pivot_longer df2 and then merge df1 and df2

library(tidyr)

merge(df1, 
      pivot_longer(df2, colnames(df2[,2:3]), 
                   names_to="Day of the week", values_to="Capacity"),
      by=c("Location","Day of the week"))
    Location Day of the week Produced Capacity
1 Location A          Monday       20       50
2 Location A         Tuesday       25       50
3 Location B          Monday       30       60
4 Location B         Tuesday       24       50
5 Location C          Monday       55       80
6 Location C         Tuesday       70       80

Data

df1 <- structure(list(Location = c("Location A", "Location B", "Location C", 
"Location A", "Location B", "Location C"), `Day of the week` = c("Monday", 
"Monday", "Monday", "Tuesday", "Tuesday", "Tuesday"), Produced = c(20L, 
30L, 55L, 25L, 24L, 70L)), class = "data.frame", row.names = c(NA, 
-6L))

df2 <- structure(list(Location = c("Location A", "Location B", "Location C"
), Monday = c(50L, 60L, 80L), Tuesday = c(50L, 50L, 80L)), class = "data.frame", row.names = c(NA, 
-3L))

Answer 2

You need to put your Capacity data into long format and then merge. Here I use tidyr::pivot_longer() for the former and then dplyr::left_join() for the latter.

library(tidyverse)

d1 <- structure(list(Location = c("Location A", "Location B", "Location C", "Location A", "Location B", "Location C"), Day_of_week = c("Monday", "Monday", "Monday", "Tuesday", "Tuesday", "Tuesday"), Produced = c(20L, 30L, 55L, 25L, 24L, 70L)), class = "data.frame", row.names = c(NA, -6L))

d2 <- structure(list(Location = c("Location A", "Location B", "Location C"), Monday = c(50L, 60L, 80L), Tuesday = c(50L, 50L, 80L)), class = "data.frame", row.names = c(NA, -3L))

d2 %>% 
  pivot_longer(-Location, names_to = "Day_of_week", values_to = "Capacity") %>% 
  left_join(d1, .)
#> Joining, by = c("Location", "Day_of_week")
#>     Location Day_of_week Produced Capacity
#> 1 Location A      Monday       20       50
#> 2 Location B      Monday       30       60
#> 3 Location C      Monday       55       80
#> 4 Location A     Tuesday       25       50
#> 5 Location B     Tuesday       24       50
#> 6 Location C     Tuesday       70       80

^{Created on 2022-02-17 by the reprex package (v2.0.1)}