Equidistant Conic Graticule Generator Script

[Hai-Etlik]

I've written a little Ruby program to generate a graticule for the equidistant conic projection. This projection works reasonably well (For fantasy map making purposes) for medium scale maps, particularly in middle latitudes. Countries to mid sized continents.

http://draconic.ca/eqd-conic.rb

It requires Ruby 1.9 to run and includes instructions in comments at the top of the file. It has a command line interface and produces SVG output you can use in Inkscape or other vector graphics editors.

A good rule of thumb is to pick standard parallels 1/6 of the way in from the top and bottom of your map.

[Hai-Etlik]

Here are some examples of the output, rendered in Inkscape.

g15091.png
grat.png

Both have standard parallels of 42° 54°, which are marked in green. The tropics are in red and the arctic and antarctic circles are in blue (Based on a tilt of 23.44°). The green lines are there as guides and should be deleted in most cases. You can restyle the red and blue lines, or delete them as you see fit.

[Lukc]

I approve

[Hai-Etlik]

Made an update. It's still command line, but now uses an option parser so it's easier and there are default values for options that aren't provided. It also now supports selecting just a section of the graticule rather than the whole globe.