create your own package

library("usethis")
create_package(path = "../package_name")
use_description()
usethis::is_package()

load library

library(devtools)
load_all() # Cmd/Ctrl + Shift + L

# use_pipe()
use_package("dplyr")

You also need to modify your description file

Imports:
  ggplot2
  dplyr

# install all dependencies in DESCRIPTION
install_deps()

create function

your_own_function <- function(){
  
}

Test your package

test() # Cmd/Ctrl + Shift + T

check Malcolm Barrett’s slides for more detail