# Changing the centroid of a geometry object

Question asked by clm42 on Oct 8, 2012
Latest reply on Oct 24, 2012 by nimitz
Whats the easiest way to move one geometry to the center of another geometry? That attribute is read only. Im generating polygons and writing them out to a row in a script. Right now the first point of my geometry object is the centroid of a parcel which means the drawings intersect the correct parcel but are not centered on it. I just tried adding the difference between the parcel centroid and the geometry centroid but while that moved the new geometry it didnt move it to the centroid as
I had hoped. Below is what I tried, parcelLookup is a nested dictionary that has all of the parcel numbers with their centroids.

`def addGeometry(inGeometry,parcelID,buildingNum,row):     diffX = (parcelLookup[parcelID]['x'] - arcpy.Geometry('polygon',inGeometry).centroid.X)     diffY = (parcelLookup[parcelID]['y'] - arcpy.Geometry('polygon',inGeometry).centroid.Y)     for i in range(0,inGeometry.count):         oldPoint = inGeometry.getObject(i)         newPoint = arcpy.Point(oldPoint.X + diffX, oldPoint.Y + diffY)         inGeometry.replace(i,newPoint)     row.shape = arcpy.Geometry('polygon',inGeometry)     row.PID = parcelID     row.Id = buildingNum     rows.insertRow(row)`

Edit: I was subtracting the centroid of the parcel from the centroid of the geometry. Thats backwards. Subtracting the geometry from the parcel is the right order. Cursed be all typos.