Recognizing Sketches of Euler Diagrams Drawn with Ellipses

Euler diagrams form the basis of a number of visual languages. However, the existing tool support for creating Euler diagrams is limited to generic diagram editing software that uses mouse and keyboard interfaces. A more natural and convenient mode of entry is via a sketching interface. In addition, it is known that sketching, as opposed to using an editing package, facilitates greater cognitive focus on the task of diagram creation. This paper presents the first sketch tool for Euler diagrams. In particular, we describe the recognition mechanism and conversion that takes a sketched Euler diagram and converts it into a formal diagram drawn with ellipses and circles. The semantics of the sketch is computed.