Suppose I have a table with chess players pairs (just an imaginary example). The table shows who played white, black and the number of games between the players.
| White| Black| Games|
|:---- |:------:| -----:|
| Anand| Caruana| 13 |
| Carlsen| Naka| 12 |
| Caruana| Giri| 14 |
| Giri| Anand| 10 |
| Grischuk| Carlsen| 7|
What I want is the total number of games (Black+White) per player, i.e. all the games he played against any other grandmaster.
| Player | Games_total|
|:---- |:------:|
| Anand| 33|
| Caruana| 27|
| Carlsen| 21|
| Naka| 12|
| Giri| 34|
| Grischuk| 9|
You may get the data in long format and then sum the Games for each Player.
library(dplyr)
library(tidyr)
df %>%
pivot_longer(cols = c(White, Black), values_to = 'Player') %>%
group_by(Player) %>%
summarise(Games_total = sum(Games))
# Player Games_total
# <chr> <int>
#1 Anand 23
#2 Carlsen 19
#3 Caruana 27
#4 Giri 24
#5 Grischuk 7
#6 Naka 12
data
df <- structure(list(White = c("Anand", "Carlsen", "Caruana", "Giri",
"Grischuk"), Black = c("Caruana", "Naka", "Giri", "Anand", "Carlsen"
), Games = c(13L, 12L, 14L, 10L, 7L)), row.names = c(NA, -5L), class = "data.frame")