Topic: Point3d coordinates...what type are the x and y coordinates?

[Proctor]

Hello: In my application, I'm looping through a polyline the user selects and getting a point at a distance (as a point3d). There's a lot that happens after that...but to make a long story short, the x and y coordinates get converted to singles and stored into a collection as nodes. Later in my app, I need to see if the point is on the polyline; however, because I converted them to singles, it doesn't find the point on the poly...and so my first question I'm curious about is when I create a point as point3d, what type of number are the x and y coordinates?

I'm also wondering if there is anyway to convert the coordinates back so that they match what ever type they were originally so that i can detect if the point is on the poly?

Hope this makes sense...let me know if not.

Thanks,
Proctor

[huiz]

X and Y are doubles.

You can also save the points as point3d in a point3dcollection.

Further you can keep the polyline in a polyline object so you can refer to that all the time, instead of single points.

[Proctor]

huiz
 Thanks so much for your reply...it's good to know that those coordinates are doubles.
There's lots of calculations that are taking place in my application and so I need to have the values as singles. Although I do store these origional points into a collection,
only some of them are converted into nodes (which are essentially points as singles) and then edges are created with these.
do you know if there's anyway to reverse a single to a double? that would be the easiest solution if it's possible.

thanks again,
Proctor

[RMS]

Try this out:

Code: [Select]

    <CommandMethod("mtest")> _
    Public Sub ListEntities()

        Dim s As Single = 22.5
        Dim d As Double = 0.0

        d = CType(s, Single)

        MsgBox(d.ToString)


    End Sub


[MCOONROD]

You are probably aware of this but I have to throw it out there. There is a lot of accuracy loss in a double to single and back conversion.

[huiz]

There also might not be a reason to convert all the time, you can refer to X and Y of a point with Point3D.X and Point3D.Y too.