There are three functions (GeoListPlot, GeoGraphics and Entity) related to working with geographic regions but it is not clear from the documentation how to create new Entities or custom geographic regions. For example, in some cases a person might want to create a new entity from an existing entity either by modifying its borders using custom coordinates, or by adding/subtracting existing entities (such as if one country annexed another). I am not talking about making geographic groups, but actually creating a new region.

Is the proper action to create an Entity or are Entities only created by Wolfram (built-in)? If you can't create your own Entities, then what is the right way to work with custom geography. For example, let's say you wanted to create a globe of the Mapparium which depicts the world as it was in 1934:


Many of the countries had borders different than those they have today. What would be the proper (or reasonably efficient way) to create the necessary region objects?


1 Answer 1


Since release of Wolfram Language 11 users can define their own entities with:


  "MyType" -> <|

    "Entities" -> <|
      "e1" -> <|"p1" -> 1, "p2" -> 2|>,
      "e2" -> <|"p1" -> 3, "p2" -> 4|>

In[6]:= Entity["MyType", "e1"]["p1"]
Out[6]= 1
  • $\begingroup$ This is what I did for the question How to plot data by counties? One can read in that answer what properties the entities should have. I also show how to create new regions out of existing regions, by using ParentEntity and DefaultFunction. $\endgroup$
    – C. E.
    Commented Apr 26, 2017 at 21:10
  • $\begingroup$ @C.E. this is very nice! Could you make a contribution crosspost on Wolfram Community so we can place it in editorial Staff Picks? wolfr.am/StaffPicks $\endgroup$ Commented Apr 26, 2017 at 22:05
  • 1
    $\begingroup$ It is now on Wolfram Community, here. $\endgroup$
    – C. E.
    Commented Apr 28, 2017 at 5:02
  • $\begingroup$ @C.E. wonderful, thank you! It has been added to wolfr.am/StaffPicks $\endgroup$ Commented Apr 28, 2017 at 11:55

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