arcview

Adding X,Y Centroids to Polygons in ArcGIS ArcView

Creating a centroid point file from a polygon in ArcEditor or ArcInfo is quick and painless.  In ArcToolBox go to Data Management Tools/Features/Feature to Point and follow instructions.

There is a downside to this convenience however.  8,910 dollars of them in fact, the cost of an ArcInfo license.

How to calculate centroids in ArcView.

  1. In the attribute table of your polygon layer and under Options choose Add Field.
    Add Field

     

  2. Add an X and Y field of type Double
    Add Field Dialog
  3. Right-click on the New X Column Header and choose Field Calculator.

     
  4. In the Field Calculator Dialog that opens, click Help

    Here's all the instructions you need, but they are written in ESRI.  Allow me to translate.  Copy this section:
      Dim Output As Double
      Dim pArea As IArea
      Set pArea = [Shape]
      Output = pArea.Centroid.X

    Paste it into Field Calculator.  Check Advanced, and enter Output into the final textbox.

    Like this:
    Field Calculator

     

  5. Click OK and repeat for Y.

You now have the X,Y coordinates of the polygon centroids.  If you really need a separate point layer, copy the DBF file for your polygon layer to a new file and add as a point layer using the Add X,Y Data... dialog under the Tools menu.