Dear UseRs, I have a question regarding reading the coordinates within a country' map. I drew map of ireland by using the following commands library("maps") library("mapproj") map("world", "ireland") map.axes() You can clearly see the axis labelled. What is want to do is to draw lines (both vertically and horizontally ) at an interval of 0.5. Which means if x-axis starts from -10 then the first be on -10 and second on -9.5 and so on. Similar has to be the case with y-axis. Afterwards I only want to read the coordinates of the point falling with in the boundary of ireland. I spent quite sometime while going through the previous posts but couldnt find the answer. Thankyou very much in advance, Elisa [[alternative HTML version deleted]]