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.

This exercise is part of the course

Intermediate R

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Exercise instructions

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.

Hands-on interactive exercise

Have a go at this exercise by completing this sample code.

# 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))

Edit and Run Code