draw a parable

Víctor García
Víctor García
in Linux
Hi everybody,

I need to draw a parable. Somebody know how to do it with spline? It's possible?
I have changed the configuration for spline to cuadratic, but when I draw it, if I see his property, I always get grade 3 (cubic)

Help, please....

Thank you very much

Comments

  • Tijs Vermeulen
    Tijs Vermeulen
    One way to obtain a parabola (it indeed results in a spline) is using a cone and a section.

    * Draw a cone
    * Draw a slant section through the cone (one that does not result in a circle or triangle)
    * This results in a region, which you can explode in a spline and a line. The spline is a parabola (well, a clipped finite version of course).

    Of course you can directly manipulate a spline, but this way can be instructive.
    I think all that it takes is a spline with 3 control points, and the middle control point has to be on the perpendicular bisector of the other two control points.

    Regards
    Tijs
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