# Applet For Drawing Exact 3 Set Area-Proportional Venn Diagrams with Convex Curves BETA Version

The ideas behind this applet are outlined in a paper published in the proceedings of Diagrams 2010.

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This applet draws a Venn diagram with 3 curves, where the areas of the regions are proportional to the input populations. It also attempts to make the curves convex, where possible. The use of the results of this applet is free for research and non profit use. Contact us for other uses. If you use the results of this applet, we encourage you to reference the paper that describes how it works:

Peter Rodgers, Jean Flower, Gem Stapleton and John Howse. Drawing Area-Proportional Venn-3 Diagrams with Convex Polygons. Proc. Diagrams 2010, LNCS 6170, pp. 54-68. Springer. 2010.

You can find a full copy of the paper here.

## Instructions

The applet draws Venn Diagrams with 3 curves. It makes each of the regions proportional to the population assigned to it.

To draw a diagram with your own data, simply type in the data for the zones in the 'population' column, and click the 'Draw Diagram' button, you should map the 3 set names of your data to A, B and C. The population values can be any you like, the program will scale them so that the diagram fits in the applet. The 'Measured Area' column shows the actual area of the regions (scaled) and so gives a confirmation that the regions are the correct area (or, if two pairs of numbers do not match, this is an indication that something has gone wrong).

By default the label in each zone is the requested population. You can create an unlabelled diagram by choosing the 'No Labels' option. The display of the curves and shading can be altered by the 'Colour', 'Shading' and 'Dashed' options.

You can get an svg (Scalable Vector Graphics) version of the picture by downloading the applet. Right click this link and choose 'Save Target As...' or similar, depending on browser. Once saved to your hard disc, double click the DiagramsApplet.jar file and (assuming your java installation is set up suitably), a more complex version of the program will appear, which includes a 'Save as SVG File' button. Using a locally saved version will also give access to a number of extra features that are described in the Diagrams 2010 conference paper, including various other diagram types.

## Known Problems

There are some cases of populations that do not produce the desired result, and we have a bug list that we will get around to sorting out at some point. If you find any inaccurate diagrams, please email us, including the populations that caused the difficulty.

## Related Work

• If you want to draw your data with three circle Venn diagrams (without exact area-proportionality) use the 3 Circle Venn Applet applet.
• If you want to draw two circle Venn diagrams (with exact area-proportionality) use the DrawVenn applet.
• Constructing these sorts of diagram is a fascinating problem. For more information on Venn Diagrams see the Venn Diagram Survey.

Ideas used to generate this work were developed by
Peter Rodgers, University of Kent, UK; Jean Flower, Gem Stapleton and John Howse, University of Brighton, UK
Contact: Peter Rodgers (email)

This research forms part of the Visualization with Euler Diagrams project, funded by EPSRC grants EP/E011160/1 and EP/E010393/1. The work has also been supported by grants EP/H012311/1 and EP/H048480/1.