generating regular grid inside irregular polygon in R

Question

I have an irregular polygon (an area of the Pacific Ocean off Mexico), and I would like to create a regular grid (say 1/2° x 1/2°) inside that polygon. I have some points inside that polygon, and I would like to add all the points that lie inside those 1/2° x 1/2° squares. I think I can do that by using the tapply function (with "sum"), but I need to create the grid first. any suggestions? Thank you

Answer 1

Try to use the polygrid function. This function is in the geoR package and it basically creates a grid in a rectangle and extracts only the points that are inside your polygon.