I'm working on a March Madness project. I have a data frame df.A
with every team and season.
For example:
Season Team Name Code
2003 Creighton 2003-1166
2003 Notre Dame 2003-1323
2003 Arizona 2003-1112
And another data frame df.B
with game results of of every game every season:
WTeamScore LTeamScore WTeamCode LTeamCode
15 10 2003-1166 2003-1323
20 15 2003-1323 2003-1112
10 5 2003-1112 2003-1166
I'm trying to get a column in df.A
that totals the number of points in both wins and losses. Basically:
Season Team Name Code Points
2003 Creighton 2003-1166 20
2003 Notre Dame 2003-1323 30
2003 Arizona 2003-1112 25
There are obviously thousands more rows in each data frame, but this is the general idea. What would be the best way of going about this?
CodePudding user response:
Here is another option using tidyverse
, where we can pivot df.B
to long form, then get the sum for each team, then join back to df.A
.
library(tidyverse)
df.B %>%
pivot_longer(everything(),names_pattern = "(WTeam|LTeam)(.*)",
names_to = c("rep", ".value")) %>%
group_by(Code) %>%
summarise(Points = sum(Score)) %>%
left_join(df.A, ., by = "Code")
Output
Season Team.Name Code Points
1 2003 Creighton 2003-1166 20
2 2003 Notre Dame 2003-1323 30
3 2003 Arizona 2003-1112 25
Data
df.A <- structure(list(Season = c(2003L, 2003L, 2003L), Team.Name = c("Creighton",
"Notre Dame", "Arizona"), Code = c("2003-1166", "2003-1323",
"2003-1112")), class = "data.frame", row.names = c(NA, -3L))
df.B <- structure(list(WTeamScore = c(15L, 20L, 10L), LTeamScore = c(10L,
15L, 5L), WTeamCode = c("2003-1166", "2003-1323", "2003-1112"
), LTeamCode = c("2003-1323", "2003-1112", "2003-1166")), class = "data.frame", row.names = c(NA,
-3L))
CodePudding user response:
We may use match
(from base R
) between 'Code' on 'df.A' to 'WTeamCode', 'LTeamCode' in df.B to get the matching index, to extract the corresponding 'Score' columns and get the sum (
)
df.A$Points <- with(df.A, df.B$WTeamScore[match(Code,
df.B$WTeamCode)]
df.B$LTeamScore[match(Code, df.B$LTeamCode)])
-output
> df.A
Season TeamName Code Points
1 2003 Creighton 2003-1166 20
2 2003 Notre Dame 2003-1323 30
3 2003 Arizona 2003-1112 25
If there are nonmatches resulting in missing values (NA
) from match
, cbind
the vectors to create a matrix
and use rowSums
with na.rm = TRUE
df.A$Points <- with(df.A, rowSums(cbind(df.B$WTeamScore[match(Code,
df.B$WTeamCode)],
df.B$LTeamScore[match(Code, df.B$LTeamCode)]), na.rm = TRUE))
data
df.A <- structure(list(Season = c(2003L, 2003L, 2003L), TeamName = c("Creighton",
"Notre Dame", "Arizona"), Code = c("2003-1166", "2003-1323",
"2003-1112")), class = "data.frame", row.names = c(NA, -3L))
df.B <- structure(list(WTeamScore = c(15L, 20L, 10L), LTeamScore = c(10L,
15L, 5L), WTeamCode = c("2003-1166", "2003-1323", "2003-1112"
), LTeamCode = c("2003-1323", "2003-1112", "2003-1166")),
class = "data.frame", row.names = c(NA,
-3L))