' Fast neighbors.ave

' This script is used for checking for neighbors, containment
' and overlaps.

' It was written by Timothy S. Thomas.
' Editing began on 11/27/00, and was last edited on 11/27/00.
' It is based on "Find neighbors little program".

' **********************************************************
' Set up basic variables
' **********************************************************

' This tells Arc/View that numerical output will be integer only.
' If we wanted decimal places, we would use something like
' "d.dd"
Script.The.SetNumberFormat("d.dd")

theProject = av.GetProject
theView = av.GetActiveDoc
theThemeList = theView.GetActiveThemes
theTheme = theThemeList.Get(0)
theFTab = theTheme.GetFTab
numRecs = theFTab.GetNumRecords

' "Shape" is a special word in FTabs
shapeField = theFTab.FindField("Shape")

' Permits changes to be made to the FTab
theFTab.SetEditable(True)


' **********************************************************
' This allows the user to pick a field as the basic unit for
' evaluation.
' **********************************************************

' Gets new field list, reflecting deletions of fields
fieldList = theFTab.GetFields.Clone
fieldList.Insert("<None>")
idField = MsgBox.ChoiceAsString(fieldList,"Select ID field",
            "Choose ID field")


' **********************************************************
' Make a comma-delimited file to hold neighbor codes
' **********************************************************

' Shows message in message bar
av.ShowMsg("Creating neighbor file")

' Creates file
FTabFN = theFTab.GetSrcName.GetFileName
baseString = FTabFN.GetBaseName
extString = FTabFN.GetExtension
newString = FTabFN.AsString.Substitute(baseString,"")
new2String = baseString.Substitute(extString,"csv")
neighborFN = FileDialog.Put(
          (newString + "neighbor " + new2String).AsFileName,
          "*.csv","Data file name")
neighborFile = LineFile.Make(neighborFN,#FILE_PERM_WRITE) 

msg1 = "Divide by this to convert map units to area units"
areaconv = MsgBox.Input(msg1,"Converstion factor","10000").AsNumber
                                                 

for each recnum in 0..(numRecs-1)

  thePoly = theFTab.ReturnValue(shapeField,recnum)
  theFTab.SelectByPolygon(thePoly,#VTAB_SELTYPE_NEW)

  for each s in theFTab.GetSelection

    otherPoly = theFTab.ReturnValue(shapeField,s)

    ' The reason for doing the following multiple area computation 
    ' is that sometimes intersecting one way incorrectly returns 
    ' 0 for area.

    area = thePoly.ReturnIntersection(otherPoly).ReturnArea
    if (area.IsNull) then
      area = otherPoly.ReturnIntersection(thePoly).ReturnArea
    end

    if (area.IsNull.Not) then
      
      area = area / areaconv
      area1 = thePoly.ReturnArea / areaconv
      area2 = otherPoly.ReturnArea / areaconv
        
      ' The CONTAINS command does not seem to select containment
      ' when the interior polygon shares a border with the
      ' exterior polygon.  Therefore, those that share a boundary
      ' but are otherwise contained may appear in the overlapped
      ' category, though I have tried to adjust for this below.

      if (thePoly.Contains(otherPoly)) then

       	extraString = ", Contains, "

      elseif (otherPoly.Contains(thePoly)) then

        extraString = ", Contained by, "

      else

        if ((area > (0.95*area1)) Or (area > (0.95*area2))) then
        
          if (area1 > area2) then
            extrastring = ", Contains probable (w/ bdry share), "
          else
            extrastring = ", Contained by probable (w/ bdry share), "
          end
          
        else

          extraString = ", Overlap, "
          
        end

      end
      
      extrastring = extrastring + area.AsString + " , "  
        + area1.AsString + " , "  + area2.AsString


    else

      extraString = ""

    end

    ' Writing a line of output to the file

    id2 = theFTab.ReturnValueString(idfield,s)
    id = theFTab.ReturnValueString(idfield,recnum)
    if (id<>id2) then
      theString = id + ", " + id2 + extraString
      neighborFile.WriteElt(theString)
    end

  end

  av.SetStatus(100*(recnum+1)/numrecs)

end

' Clears selected features in the theme and theme table
theTheme.ClearSelection

' Clears message in message bar
av.ClearMsg

' Turns off editing in the FTab
theFTab.SetEditable(false)

' Removes garbage objects
av.PurgeObjects