(Using textbook: Categorical Data Analysis 3rd Edition, by Alan Agresti)

How can I write a function that calculates G^2 (full formula on page 76) for a contingency table. The function should calculate G^2 for the party vs race table (on page 105).

This is a biostatistics question, and it needs to be coded in R Studio, not using any built-in formulas. I am not sure how to write the formula.

Thank you!