## 1.3 Help files

It is nearly impossible to remember all the function names and all their arguments by heart. Fortunately enough, every function and argument in R is required to be documented in dedicated help files. The user is highly encouraged to always refer to the documentation in case of doubt on how to use this function.

There are multiple ways to access a specific help file. The safest way to do so is by calling a function with a preceding question mark ?.

?mean()

If you are using the RStudio IDE (most likely), the is a more convenient way of accessing a specific help file. When typing the function’s name in the R console or in a script file (.R, .Rmd, …) just left click on the name and press F1.

Sometimes it might happen that you do not know the exact name of a function though. To quickly navigate to an R package’s content, ie. a list of its included functions, it is easiest to use the help() function.

help(package = "Luminescence")

Be aware to explicitly use the package argument and not call help("Luminescence"), which would be interpreted as help(topic = "Luminescence") as topic is the first argument of this function. This will then open the help file to the package itself, which, actually, is not a great help (unless you wanted to have a look at the list of authors…).