Drawing Interactive Euler diagrams from Region Connection Calculus Specifications


The aim of the software is to generate interactive drawings with circles (for instance Euler diagrams) from a set of constraints. Instead of using the mouse, you write constraints in Region connection calculus. The advantage is that you are sure when desired constraints are satisfied. It is open source: source

Constraint editor

In the left part, you write your constraints. Here are some explanations of the constraints you may write:

circle("A"); We create a circle called "A"
radius("A",30); The radius of the circle called "A" should be 30
EC("A", "B"); The circles named "A" and "B" are externally connected
DC("A", "B"); The circles named "A" and "B" are disconnected
PO("A", "B");
 The circles "A" and "B" are partially overlapping.
TPP("A", "B");
 The circle "A" is a tangential proper part of the circle "B".
NTPP("A", "B");
 The circle "A" is a non-tangential proper part of the circle "B".

 On the left of the text zone, there is a palette to help you to add constraints to your drawing.

When you edit the text zone, click on update to update the drawing.

Drawing zone

On the right part of the screen, you see the drawing that is produced. You can move the circles to change the drawing. The software continues to use search in background so that the constraints are satisfied (or the most satisfied as possible).

You may pause/resume the search algorithm.