I am trying to estimate the mutual information between vit level (values vary from 4 to 70, all of which are whole numbers) and a binary variable that indicates the presence of polyps. I am not sure if I should first discretize the vit variable. If I do, I am not sure how many bins to choose. Any pointers would be appreciated.
When I draw box-plots, I can see there is some association but my code estimates mutual information of 0.006.
This is my R code at the moment:
freqs2d = rbind( vit, polyps) H1 = entropy.plugin(rowSums(freqs2d)) H2 = entropy.plugin(colSums(freqs2d)) H12 = entropy.plugin(freqs2d) H1+H2-H12