Rstudio Project -- 2

The project should be solved in a single R file. The file should contain the solution (implementation) and examples of use (you can use the above examples). Solutions without examples will not be excepted. You are not allowed to use any additional packages except for dplyr, ggplot2 for plots and R6 if you choose to implement the solution with the R6 object model. Please, do not use polish diacritics (or any other).
Deadline 24-36 hours from start.