Postal codes in Canada

This is a partial answer dealing with cleaning up your postal code regions. Suppose you use a convex hull to get a bunch of vertices that define polygons.

library(polyclip)
library(ggplot2)

canada <- data.frame(x = c(0,1,1,0),
                     y = c(0,0,1,1))
postcode1 <- data.frame(x = c(0.5, 1.5, 1.5, 0.8),
                        y = c(0.5, 0.8, 1.5, 1.5))
postcode2 <- data.frame(x = c(0.25, 0.75, 0.75, 0.25),
                        y = c(0.25, 0.25, 0.75, 0.75))

ggplot() +
    geom_polygon(data = canada, aes(x,y), fill = "lightblue", color = "blue", alpha = 0.5) +
    geom_polygon(data = postcode1, aes(x,y), fill = "lightgreen", color = "green", alpha = 0.5) +
    geom_polygon(data = postcode2, aes(x,y), fill = "pink", color = "red", alpha = 0.5)

You can see that the convex hulls of the postal code regions overlap each other, and one of them extends outside of the country. The polyclip package lets you take intersections, unions, xor and setdiff of the regions bounded by the vertices.

clip1 <- polyclip(postcode1, canada, "intersect")[[1]] |> as.data.frame()
clip2 <- polyclip(postcode2, clip1, "minus")[[1]] |> as.data.frame()

ggplot() +
    geom_polygon(data = canada, aes(x,y), fill = "lightblue", color = "blue", alpha = 0.5) +
    geom_polygon(data = clip1, aes(x,y), fill = "lightgreen", color = "green", alpha = 0.5) +
    geom_polygon(data = clip2, aes(x,y), fill = "pink", color = "red", alpha = 0.5)

Happy clipping!