match point data to country/state/region boundary polygon

point.2.poly

# Matching point records to polygones boundaries of a country, state or
# region polygones for regions of NZ
require(maptools)
library(maps)
library(SDMTools)
# obtain lon/lat boundaries for north and south island of NZ
nz.n.poly <- cbind(map("nz", regions = "North.Island")$x, map("nz", regions = "North.Island")$y)
nz.s.poly <- cbind(map("nz", regions = "South.Island")$x, map("nz", regions = "South.Island")$y)

# match to points where d[(6:5)] are the columns of a dataframe containing lon/lat data
d1$north <- as.factor((pnt.in.poly(d[(6:5)], nz.n.poly))$pip)
d1$north <- gsub(1, "north", d1$north)
d1$south <- as.factor((pnt.in.poly(d[(6:5)], nz.s.poly))$pip)
d1$south <- gsub(1, "south", d1$south)

d2 <- d1[which((d1$north == "north") | (d1$south == "south")), ]