Math geometry help

[PanHasan]

Hi

how can i get the coordinates of point P2' I've got P1,P2 length between them and the angle between those lines

 

[rkmcswain]

Using lisp, the POLAR function should do it.

[SEANT]

I suspect this is a .Net question. If that is true then there is an option to Interop ThisDrawing.Utility.PolarPoint.

 

or

 

Create a .AutoCAD.Geometry Vector3d by:

 

Vector = P1.GetVectorTo(P2)

P2’ = P1.Add(Vector.RotatedBy(ang, new Vector3d(0,0,1))

 

 

If you want to do the calculations directly, The Math/Trigonometry is shown in the attached spreadsheet.

PolarPoint.zip

[paulmcz]

Hi

how can i get the coordinates of point P2' I've got P1,P2 length between them and the angle between those lines

 

 

Is the length P1 P2' the same as P1 P2?

[PanHasan]

Yes the length of P1-P2 and P1-P2' is the same but SEANT has already solved my problem as always thx very much

[gile]

Hi,

 

Here're are two Polar extension methods for the Point2d and Point3d classes which work as the polar LISP function:

3 arguments:

- a 2d or 3d point

- an angle expressed in radians relative to the world X axis

- the distance from the point

 

public static Point2d Polar(this Point2d org, double angle, double distance)
{
   return new Point2d(org.X + (distance * Math.Cos(angle)), org.Y + (distance * Math.Sin(angle)));
}

public static Point3d Polar(this Point3d pt, double angle, double distance)
{
   return pt.Add(new Vector3d(distance, 0.0, 0.0).RotateBy(angle, new Vector3d(0.0, 0.0, 1.0)));
}

[Bill Tillman]

Wrap a chainsaw around my neck and call me the missing link, but wouldn't it be simpler to just right click on the line from P1 to P2' and view it's properties....? Unless you're doing this for many points, I can't see the advantage of coding.

[PanHasan]

Exactly I'm doing it for many points and the angle is changing for each of it i used the SEANTS solution and its work for me ;p