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  1. #1
    Junior Member
    AutoCAD 2011
    Join Date
    Jun 2011

    Default Equation Of A Spline that passes 4 points

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    Hello all

    I was hoping someone could shed some light on the following:-

    I have a spline that goes through 4 points:-

    x1,y1 - x2,y2 - x3,y3 - x4,y4

    The spline is of degree 3 and is fixed at points x1, y1 and x4, y4.

    What i need is the equation of the spline.

    Is there anyway of calculating the equation that represents the spline?


  2. #2
    Forum Deity Organic's Avatar
    AutoCAD not applicable
    Join Date
    Feb 2009


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    It should be possible, although it is a huge pain to do so. I remember having to do it back in college, although have never used it since.

    The general method is outlined in http://mathworld.wolfram.com/CubicSpline.html

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