CODEWITHSUNDEEP
rclassif-statement
Alfredo
Alfredo

Reputation: 125

How to check if values in two columns has the same class in R?

I have to check if a value in two columns or lists has the same class. I wrote the following codes but none are working because just write the last value on the list but not only the first values.

My lists

x <- c(1,3,6,2) ## All are numeric
y <- c(6,4,3,'a') ## Note that is a string at here
m <- NULL

Code 1

for (i in length(x)) {
  if (class(x[i]) == class(y[i])) m[i] <-'ok' else m[i] <- 'no ok'
}

Code 2

et <-function(x, y){
  for (i in length(x)) {
    if (class(x[i]) == class(y[i])) {
      m[i] = 'ok'
    } else {
      m[i] = 'not ok'
    }
    return(f)
  }
}
et(x,y)

Thanks for helping.

Upvotes: 0

Views: 370

Answers (3)

akrun
akrun

Reputation: 886998

We can also loop through using lapply/sapply and get a logical output

 sapply(seq_along(x), function(i) class(x[[i]])==class(y[[i]]))

data

x <- list(1,3,6,2)   
y <- list(6,4,3,'a')

Upvotes: 0

akuiper
akuiper

Reputation: 214917

If you want to check the class of corresponding elements in two lists, you can use Map function:

x <- list(1,3,6,2)   
y <- list(6,4,3,'a')
Map(function(x,y) c("no ok", "ok")[as.integer(class(x) == class(y)) + 1], x, y)
[[1]]
[1] "ok"

[[2]]
[1] "ok"

[[3]]
[1] "ok"

[[4]]
[1] "no ok"

Or mapply which returns a vector:

mapply(function(x,y) c("no ok", "ok")[as.integer(class(x) == class(y)) + 1], x, y)
[1] "ok"    "ok"    "ok"    "no ok"

Upvotes: 2

rosscova
rosscova

Reputation: 5580

Your problem is in the for loop call, which is only passing one integer to run, rather than a list of integers, like you're hoping. Change this:

for (i in length(x)) { ...

to this:

for (i in 1:length(x)) { ...

Notice that "length(x)" is 4, whereas "1:length(x)" is all integers 1:4.

Upvotes: 3

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