Chapter 5 Functions

You’ll need to organize your code into functions in order to use the code in a package.

Function structure:

foo <- function(x) {
  x^2
}

You can call the function

foo(5)

#> [1] 25

5.1 Exercise

Write your own function

• Write a function
• Run it!
• Any problems? report back

5.2 Functions in a package

In a real R package you DO NOT want to export all functions in the package.

RStudio/devtools/usethis/etc. do put

exportPattern("^[^\\.]")

in your NAMESPACE file by default.

Important: Make sure to remove this and explicitly export functions that you want users to use with RStudio buttons or devtools::document() or similar.