CODEWITHSUNDEEP
rdataframegroup-bydplyr
Shin
Shin

Reputation: 107

DataFrame operation R

I'm trying to assign a variable in data frame according to specific another column variable. i.e.

Dta = matrix(0,10000,2)
colnames(Dta) <- c("School_ID","Class_ID")
Dta = as_data_frame(Dta)
Dta$School_ID = sample(100)
Dta$School_ID = sort(Dta$School_ID)
for (i in unique(Dta$School_ID) ) Dta[Dta$School_ID == i,'Class_ID'] = sample(5)

Is there any solution by using group_by or other operators without a loop?

Upvotes: 1

Views: 46

Answers (1)

www
www

Reputation: 39154

Here is a solution from dplyr. dt2 is the final output.

# Load package
library(dplyr)

dt <- data_frame(School_ID = rep(1:100, each = 100))

dt2 <- dt %>%
  group_by(School_ID) %>%
  mutate(Class_ID = rep(sample(5), 20))

Upvotes: 1

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