CODEWITHSUNDEEP
rfor-loopapplylapplysapply
mrsquid
mrsquid

Reputation: 635

R For loop with if statement to Apply format

Say I have a for loop that looks like this.

person <- c("Mike", "Kim", "Fred", "Steve", "Quail", "bean")

sleep <- c(5, 10, 3, 7, 1, 5)


dat <- data.frame(person, sleep)

for (i in 1:length(dat$person)) {
 if (dat$sleep[i] >= 7) {
   dat$fatigue[i] <- 0
 }
 if (dat$sleep[i] > 5 & dat$sleep[i] < 7) {
   dat$fatigue[i] <- 1
 }
 if (dat$sleep[i] >= 3 & dat$sleep[i] <= 5) {
   dat$fatigue[i] <- 2
 }
 if (dat$sleep[i] < 3) {
  dat$fatigue[i] <- 3
 }
}

How would I write this for loop with the if statements using the apply functionality of R?

I am rather new to using this and any help would be appreciated.

Please let me know if you have any questions.

Thank you.

Upvotes: 1

Views: 123

Answers (2)

Hunaidkhan
Hunaidkhan

Reputation: 1443

if you want to use nested ifelse this solution can be useful using baseR 

person <- c("Mike", "Kim", "Fred", "Steve", "Quail", "bean")

sleep <- c(5, 10, 3, 7, 1, 5)

dat <- data.frame(person, sleep)

dat$fatigue <- ifelse(dat$sleep < 3,3,ifelse(dat$sleep >= 3 & dat$sleep <= 5, 2,ifelse(dat$sleep > 5 & dat$sleep < 7,1,ifelse(dat$sleep >= 7, 0,"NA"))))
)

Upvotes: 2

Tim Biegeleisen
Tim Biegeleisen

Reputation: 522234

We can try using case_when from the dplyr library

dat$fatigue <- case_when(
    dat$sleep < 3 ~ 3,
    dat$sleep >= 3 & dat$sleep <= 5 ~ 2,
    dat$sleep > 5 & dat$sleep < 7 ~ 1,
    dat$sleep >= 7 ~ 0,
    TRUE ~ -1
)

Note that case_when(), like many functions in R, is already vectorized. Therefore, you don't need to use an explicit for loop.

Upvotes: 1

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