The main purpose of this recipe is to call attention to the fact that gnuplot comes with a very useful datafile called
world.dat. This consists of coordinates for a rough outline of the Earth's land masses, as latitude and longitude in the usual degree units. It can be used as a map background for plotting other geographically relevant data. In the following figure, we've overlaid some data on recent earthquake activity:
We've included a copy of the
world.dat datafile in case you've mislaid the one that comes with gnuplot. You also need to have the file
earthquakes.dat. This contains data from the United States Geological ...