The polar form of a conic with one focus fixed at
the origin (pole) has one of the following forms:
r = p/(1+ε·cos(t−φ)
r = p/(1−ε·cos(t−φ)
r = p/(1+ε·sin(t−φ)
r = p/(1−ε·sin(t−φ)
where ε is the eccentricity, ε≥0, |p| is the semi-latus-
rectum, and φ is the tilt angle, 0≤φ≤π.