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Thread: *** Resolved *** Plot Ellipse

  1. #1

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    Thumbs up *** Resolved *** Plot Ellipse

    According to the picture, I'd like to have the code to plot point "P" , (X,Y), coordinates.

    Thanks in advance.

    Regards

    DSerkez
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    Last edited by DSERKEZ; Jul 7th, 2003 at 09:44 AM.

  2. #2
    Fanatic Member twanvl's Avatar
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    If C is at (0,0), then the condition:
    x2/a2 + y2/b2 = 1
    will be true for all points on the ellipse.
    So for a given x:
    y2/b2 = 1 - x2/a2
    y2 = (1 - x2/a2) * b2
    y = +/- sqrt((1 - x2/a2) * b2)

    where +/- means that y can have two values, +... and -...., and sqrt is the square root (?0.5)

    You could also calculate the ellipse based on:
    r1 + r2 = 2(a-c) + 2c = 2a

  3. #3

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    Plot Ellipse

    Hi and thank you for the reply.

    But what I am trying to do is to move point "P" around the ellipse and connecting two lines (F1,F2) to P while moving.

    I tried some things but did not work.


    Thanks again.

  4. #4
    pathfinder NotLKH's Avatar
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    So, you mean something like this example progie, except for an ellipse, and not a sphere?

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  5. #5

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    Thumbs up Plot Ellipse

    That's exactly what I needed.

    Thank you Twanvl, thank you NotLKH.



    Bye.

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