I'm trying to write an algorithm that will create the smallest possible ellipse to encompass any number of points on 2D euclidean space. I've gotten it to the point where I can attain the major axis A by taking the furthest two points in the set and likewise the centerpoint C as the average of those two furthest points. I now want to loop through the remaining points in the set to find the highest minor axis B value, once the two furthest points are found the remaining points are normalized to them (moved/rotated) such that the center point of the ellipse is the new (0,0) and it is going to be an ellipse with horizontal foci, my question is:(adsbygoogle = window.adsbygoogle || []).push({});

Given the centerpoint of a normalized ellipse, it's major diameter A and any point P laying on the circumference of that ellipse, how do I find the focus F, or the minor diameter B?

If this helps explain it, I have C, a and P of this diagram, I want to find b or f:

http://upload.wikimedia.org/wikipedia/commons/6/65/Ellipse_Properties_of_Directrix_and_String_Construction.svg

**Physics Forums - The Fusion of Science and Community**

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Question Regarding Ellipses

Loading...

Similar Threads - Question Regarding Ellipses | Date |
---|---|

Question regarding Munkres' proof of the Tychonoff theorem | Dec 20, 2010 |

Questions regarding tensors | Aug 29, 2010 |

Basic geometry question regarding hexagons. | Aug 4, 2010 |

Basic question regarding continuous inverses | Feb 3, 2009 |

Questions regarding function operations on sets. | Sep 19, 2008 |

**Physics Forums - The Fusion of Science and Community**