topic Line to points in Data Management Questions

Line to points

MathieuCain — Wed, 29 Jun 2011 14:31:30 GMT

Hello,

What I have:
- I have a line which is correctly geographically referenced.
- I know that the start and end nodes correspond to specific stations (i.e., points).
- The stations are sequential numbers based on some variable distance (e.g., Station 3408.52 is 2.91ft from Station 3405.61) - this distance may vary between stations.

What I want:
- I want to correctly position each station as a point along this line.

My proposed procedure:
- Create a table of all stations in sequential order, with a field containing distance to next one.
- Using the table, break the line at the set intervals (in sequential order)
- Export polyline nodes to a new point feature class (e.g., using ETGeoWizards)

Problem: How do I tackle my second step?

Re: Line to points

JonWebb — Thu, 30 Jun 2011 07:48:01 GMT

The following VB script is from http://forums.esri.com/Thread.asp?c=93&f=987&t=106536

I tested it with a mxd containing a point file and a line file, the point file being first in the TOC. Do not run it in Edit mode. It works as long as the points are not at the beginning or end of the line as this results in lines of zero length.

Sub SplitAll()
    Dim pMxDoc As IMxDocument
    Set pMxDoc = ThisDocument

    Dim pMap As IMap
    Set pMap = pMxDoc.FocusMap

    Dim pPointL As IFeatureLayer
    Set pPointL = pMap.Layer(0) 'point layer to split lines with

    Dim pLineL As IFeatureLayer
    Set pLineL = pMap.Layer(1) 'line layer to be split


    Dim pLineFC As IFeatureClass
    Set pLineFC = pLineL.FeatureClass

    Dim pPointFC As IFeatureClass
    Set pPointFC = pPointL.FeatureClass

    Dim pPointCursor As IFeatureCursor
    Set pPointCursor = pPointFC.Search(Nothing, False)

    Dim pPointF As IFeature
    Set pPointF = pPointCursor.NextFeature

    Do Until pPointF Is Nothing
        Dim pPoint As IPoint
        Set pPoint = pPointF.Shape

        Dim pSF As ISpatialFilter
        Set pSF = New SpatialFilter

        With pSF
            Set .Geometry = pPoint
            .GeometryField = "Shape"
            .SpatialRel = esriSpatialRelIntersects
        End With

        Dim pLineCursor As IFeatureCursor
        Set pLineCursor = pLineFC.Search(pSF, True)

        Dim pLineF As IFeature
        Set pLineF = pLineCursor.NextFeature

        Do Until pLineF Is Nothing
            Dim pPolyCurve As IPolycurve
            Set pPolyCurve = pLineF.Shape

            Dim pToPoint As IPoint
            Set pToPoint = pPolyCurve.ToPoint

            Dim pFromPoint As IPoint
            Set pFromPoint = pPolyCurve.FromPoint

            If (pFromPoint.X = pPoint.X And pFromPoint.Y = pPoint.Y) Then
                'do nothing
            ElseIf (pToPoint.X = pPoint.X And pToPoint.Y = pPoint.Y) Then
                'do nothing
            Else
                Dim pFeatureEdit As IFeatureEdit
                Set pFeatureEdit = pLineF
                pFeatureEdit.Split pPointF.Shape
            End If
            Set pLineF = pLineCursor.NextFeature
        Loop

        Set pPointF = pPointCursor.NextFeature

    Loop

End Sub

Re: Line to points

MathieuCain — Thu, 30 Jun 2011 11:24:21 GMT

The following VB script is from http://forums.esri.com/Thread.asp?c=93&f=987&t=106536

I tested it with a mxd containing a point file and a line file, the point file being first in the TOC. Do not run it in Edit mode. It works as long as the points are not at the beginning or end of the line as this results in lines of zero length.

Sub SplitAll()
    Dim pMxDoc As IMxDocument
    Set pMxDoc = ThisDocument

    Dim pMap As IMap
    Set pMap = pMxDoc.FocusMap

    Dim pPointL As IFeatureLayer
    Set pPointL = pMap.Layer(0) 'point layer to split lines with

    Dim pLineL As IFeatureLayer
    Set pLineL = pMap.Layer(1) 'line layer to be split


    Dim pLineFC As IFeatureClass
    Set pLineFC = pLineL.FeatureClass

    Dim pPointFC As IFeatureClass
    Set pPointFC = pPointL.FeatureClass

    Dim pPointCursor As IFeatureCursor
    Set pPointCursor = pPointFC.Search(Nothing, False)

    Dim pPointF As IFeature
    Set pPointF = pPointCursor.NextFeature

    Do Until pPointF Is Nothing
        Dim pPoint As IPoint
        Set pPoint = pPointF.Shape

        Dim pSF As ISpatialFilter
        Set pSF = New SpatialFilter

        With pSF
            Set .Geometry = pPoint
            .GeometryField = "Shape"
            .SpatialRel = esriSpatialRelIntersects
        End With

        Dim pLineCursor As IFeatureCursor
        Set pLineCursor = pLineFC.Search(pSF, True)

        Dim pLineF As IFeature
        Set pLineF = pLineCursor.NextFeature

        Do Until pLineF Is Nothing
            Dim pPolyCurve As IPolycurve
            Set pPolyCurve = pLineF.Shape

            Dim pToPoint As IPoint
            Set pToPoint = pPolyCurve.ToPoint

            Dim pFromPoint As IPoint
            Set pFromPoint = pPolyCurve.FromPoint

            If (pFromPoint.X = pPoint.X And pFromPoint.Y = pPoint.Y) Then
                'do nothing
            ElseIf (pToPoint.X = pPoint.X And pToPoint.Y = pPoint.Y) Then
                'do nothing
            Else
                Dim pFeatureEdit As IFeatureEdit
                Set pFeatureEdit = pLineF
                pFeatureEdit.Split pPointF.Shape
            End If
            Set pLineF = pLineCursor.NextFeature
        Loop

        Set pPointF = pPointCursor.NextFeature

    Loop

End Sub

Thank you for the code. While I have not had an opportunity to try it out yet, I should probably clarify as maybe it wasn't quite clear in my problem definition, that I only have a list of station names, not their actual coordinates. The only stations that I do have coordinates for are the ones at the start and end of the line. Based on this, I would like to position the other stations along this line as point features.