Results 1 to 1 of 1

Thread: Elliptical Arc-Midpoint determination

  1. #1
    May 2009

    Elliptical Arc-Midpoint determination

    I want to find the midpoint on the elliptical arc

    I know the following
    1 Start point of elliptical arc
    2 End point of elliptical arc
    3 Center Angle of elliptical arc or Sweep Angle
    4 Center point of elliptical arc
    5 Major radius of elliptical arc
    6 Minor radius of elliptical arc

    Angle (in radian) =StartAngle + (CenterAngle / 2)
    Where start angle is the angle from center point to start point in radian

    MidX = CenterX +Cos(Angle) * Distance
    MidY = CenterY+ Sin(Angle) * Distance

    Distance is the Distance from center point to Midpoint on the elliptical arc which is unknown.

    Please do help in finding the Distance which is unknown or specify some other approch to do so.

    I have tried by substituting the major radius and minor radius as X and Y Distance, but itís not giving correct result.

    I have attached the picture and also provided sample values

    Actually my elliptical arc may be horizontal(fig 1) or vertical(fig 2) or rotated (fig 3) as shown in sample picture

    For Fig 1, I have provided the point details.

    A = Start Point = ( 170.6004 , 159.3217)

    C = End Point = ( 196.1697 , 129.754)

    O = Center Point = (206.7051 , 146.6791)

    Center Angle = 283

    Start Angle = 161 ( Angle form center point to start point)

    End Angle = 283 ( Angle from center point to End point)

    Major Radius = 52.9993

    Minor Radius = 17.2697

    Mid Point = B =?

    Attached Thumbnails Attached Thumbnails Elliptical Arc-Midpoint determination-example-elliptical-arc-picture.jpg  
    Last edited by mrajee; Nov 27th 2009 at 03:25 AM. Reason: uploading picture
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Need help with B-spline determination
    Posted in the Advanced Math Topics Forum
    Replies: 0
    Last Post: May 25th 2011, 11:42 AM
  2. Replies: 3
    Last Post: Sep 12th 2010, 02:30 AM
  3. Midpoint on the elliptical arc
    Posted in the Geometry Forum
    Replies: 2
    Last Post: Nov 26th 2009, 12:31 AM
  4. midpoint of an elliptical arc
    Posted in the Geometry Forum
    Replies: 0
    Last Post: Oct 12th 2009, 01:33 AM
  5. coefficient of determination
    Posted in the Advanced Statistics Forum
    Replies: 2
    Last Post: Nov 3rd 2007, 10:59 AM

Search Tags

/mathhelpforum @mathhelpforum