对于某些功能，导入的软件包不能与R中的软件包一起使用？

Question

I built my own package. I imported the most important package that I need them in my package. In these packages there are some functions are not exported by the package (I did not find them in the namespace of the package). I need these functions. When I call them, I get an error that those funciton are not found. So, How I can solve this problem. Also, how does these packages uses this functions inside their packages without using @export!! any help please?

based on the answer:

I understand I do it like this inside my R code: I need the following function:

args <- preproc(c(as.list(environment()), call = match.call()),
               check_matrix,
                check_fammat,
                check_parmat,
                check_par2mat)
           list2env(args, environment())

Then I must do like this:

VineCopula:::preproc()

Then how to call args ?

Answer 1

You can call non exported functions with

packagename:::functionname()

It is however not recommended to do that since those functions might not be supported in future versions of packages.

If you want to use a non exported function from your own library inside your own library, you can just use functionname() altough some package developers still prefer packagename:::functionname() .