The equidistant conic projection was described by the Greek
philosopher Claudius Ptolemy about A.D. 150. It is neither
conformal or equal-area, but serves as a compromise between them.
The scale is true along all meridians and the standard parallels.
To select this projection in **GMT** you must
provide the same information as for the other conic projection, i.e.

- Longitude and latitude of the projection center
- Two standard parallels
- Map scale in inch/degree or 1:xxxxx notation
(
**-Jd**), or map width (**-JD**)

The equidistant conic projection is often used for atlases with maps of small countries. As an example, we generate a map of Cuba:

gmtset PLOT_DEGREE_FORMAT ddd:mm:ssF GRID_CROSS_SIZE_PRIMARY 0.05i pscoast -R-88/-70/18/24 -JD-79/21/19/23/4.5i -B5g1 -Di -N1/1p -Glightgray \ -W0.25p -P > GMT_equidistant_conic.ps gmtset GRID_CROSS_SIZE_PRIMARY 0