thumb|226px|An epispiral with equation r(θ)=2sec(2θ) The epispiral is a plane curve with polar equation \ r=a \sec{n\theta}. There are n sections if n is odd and 2n if n is even.
thumb|226px|An epispiral with equation r(θ)=2sec(2θ) The epispiral is a plane curve with polar equation \ r=a \sec{n\theta}. There are n sections if n is odd and 2n if n is even.
It is the polar or circle inversion of the rose curve.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).