DataFrames.jl [https://github.com/JuliaData/DataFrames.jl] provides the most
widely used tabular data [https://www.w3.org/TR/tabular-data-model/#intro]
structure in Julia. Β In this post we'll explore DataFrames using sample data
from RDatasets.jl [https://github.com/JuliaStats/RDatasets.jl] (and we'll plot