Map coordinates are normalized from 0.0 to 1.0 for each zone map.
One simple API call gets you your current x/y on the map:
x, y = GetMapPlayerPosition("player")
This.
I made an add on that tells me what surveys I have in my inventory and, if in zone, where to go to find them. I displayed the coords call as a random extra.
It has turned out to be the single most useful part.