Ellipsoidal coordinates
spatial elliptic coordinates
The numbers , and connected with Cartesian rectangular coordinates , and by the formulas
where . The coordinate surfaces are (see Fig.): ellipses , one-sheet hyperbolas (), and two-sheet hyperbolas (), with centres at the coordinate origin.
Figure: e035420a
The system of ellipsoidal coordinates is orthogonal. To every triple of numbers , and correspond 8 points (one in each octant), which are symmetric to each other relative to the coordinate planes of the system .
The Lamé coefficients are
If one of the conditions in the definition of ellipsoidal coordinates is replaced by an equality, then degenerate ellipsoidal coordinate systems are obtained.
Comments
References
[a1] | G. Darboux, "Leçons sur la théorie générale des surfaces et ses applications géométriques du calcul infinitésimal" , 1 , Gauthier-Villars (1887) pp. 1–18 |
[a2] | Harold Jeffreys, Bertha Jeffreys, Methods of Mathematical Physics, 3rd edition, Cambridge University Press (1972) Zbl 0238.00004 |
Ellipsoidal coordinates. Encyclopedia of Mathematics. URL: http://encyclopediaofmath.org/index.php?title=Ellipsoidal_coordinates&oldid=34027