Geometry.Tolerance

[StormyC]

Can anyone help with explaining how Geometry.Tolerance works...

If i compare 2 points p1 = 28,5 and p2 = 101.4,120.2 and have a tolerance object that is 0,100 the result of the comparison is true.....

Tolerance tol = new Tolerance (0,100);

Point2d pt1 = new Point2d(28,5);

Point2d pt2 = new Point2d(101.4,120.2);

bool result = pt1.IsEqualTo(pt2,tol);

result will be true but I dont understand why.... the distance between the points is 136.6 and x coordinate differance is 115.2, both out of tolerance.  So, what's the 'tolerance' doing?

Many thanks.

EDIT: It was a coding error - seems I had mixed up coordinates.....

[StormyC]

Wonder if anyone out there can enlighten me:

I now understand that Tolerance tol = new Tolerance (0,100); gives a distance tolerance of 100.  However, I do not understand what the 0 is.  Any figure in there doesnt change the outcome.  Its called "equalVector" and its type is "double".  Can anyone show me an example of how that would work?

Many thanks.

[FRFR1426 · Accepted solution]

The first argument of the tolerance constructor is used to compare vectors (default: 1e-12), the second is to compare points (default: 1e-10). Vectors are used to store directions, so there are compared with a higher tolerance than points (a small difference between angles has a bigger impact than the same difference between distances).

[StormyC]

Thanks for the reply.

So if im comparing points, the vector part will have no effect and vis versa if im comparing vectors?

[FRFR1426]

Yes. Point2d and Point3d.IsEqualTo use EqualPoint, Vector2d and Vector3d.IsEqualTo use EqualVector.