Use vapply (2)

So far you've seen that vapply() mimics the behavior of sapply() if everything goes according to plan. But what if it doesn't?

In the video, Filip showed you that there are cases where the structure of the output of the function you want to apply, FUN, does not correspond to the template you specify in FUN.VALUE. In that case, vapply() will throw an error that informs you about the misalignment between expected and actual output.

Deze oefening maakt deel uit van de cursus

Intermediate R

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Oefeninstructies

Inspect the pre-loaded code and try to run it. If you haven't changed anything, an error should pop up. That's because vapply() still expects basics() to return a vector of length 3. The error message gives you an indication of what's wrong.
Try to fix the error by editing the vapply() command.

Praktische interactieve oefening

Probeer deze oefening eens door deze voorbeeldcode in te vullen.

# temp is already available in the workspace

# Definition of the basics() function
basics <- function(x) {
  c(min = min(x), mean = mean(x), median = median(x), max = max(x))
}

# Fix the error:
vapply(temp, basics, numeric(3))

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