thumb|right|300px|Examples of 3-ellipses for three given foci. The progression of the distances is not linear.
thumb|right|300px|Examples of 3-ellipses for three given foci. The progression of the distances is not linear.
In geometry, the -ellipse is a generalization of the ellipse allowing more than two foci. -ellipses go by numerous other names, including multifocal ellipse, polyellipse, egglipse, -ellipse, and '''Tschirnhaus'sche Eikurve' (after Ehrenfried Walther von Tschirnhaus). They were first investigated by James Clerk Maxwell in 1846.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).