CODEWITHSUNDEEP
r
PandaMan
PandaMan

Reputation: 33

Return results after time limitation in for loop

I have a for loop in R iterating through a dataframe. Each row of the dataframe results in a different outcome in all the operations in the for loop. The loop is quite long, thus I want to have a time limitation for the for loop and when the time expires it should return all the results it was able to compute given the time limitation.

I tried some functions in R.utils but they don't return the result after the time limitation was met.

Upvotes: 0

Views: 33

Answers (1)

Erwin Gielens
Erwin Gielens

Reputation: 31

You could explicitly define a return statement if the desired time has passed: 

df <- data.frame(x=seq(1, 10000, 1), y=rnorm(10000,0, 1))

end.time <- Sys.time()+5
rowsum <- list()

for (i in 1:nrow(df)){
  if (Sys.time()<end.time){
    Sys.sleep(1)
    rowsum[[i]] <- sum(df[i,])
  } else {
    return(rowsum)
  }
}

dim(do.call("rbind", rowsum))
[1] 5 1

The important element is the if-else condition with the return statement. You can set the condition to any time window you prefer.

Some side notes: I set a sys.sleep command to prevent the loop from finishing before time, so you would not need that. I also saved the output in a list instead of a data frame, that is also a matter of preference.

Upvotes: 1

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