johnbarr

Spatial Interpolation on Duplicate Points

Discussion created by johnbarr on Feb 9, 2011
Latest reply on Feb 12, 2011 by Dan_Patterson
Attempting to create a surface representing property values. 
Single family homes (which are) - 1 value : 1 parcel - is simple enough, but would like to include condos, which are Many values : 1 parcel.

My data sets are:
-Polygons for Parcels (Parcel ID)
-Table with attributes: Account ID, Parcel ID, Account Value.

My methodology is to convert the Parcel Polygons to points, then join to table on Parcel ID to create a single point with Value for a single family home; however, the multiple condos values are forced to relate to a single point.

Because of condo values being coincident to the single point location, my understanding is that this is problematic.  The solution I have in mind is to place a number of random points equal to the number of units within the Condo within the region defined by the parcel polygon.  That way I have represented all values by a point within the parcel extent that it belongs to.

I am presuming that I will be using IDW to derive the surface, and therefore would like to ask if there is a tool to force the points to be distributed to an region that is defined by each parcel polygon.

Or is this a good example why another method to derive the surface should be used, ie Kriging?

Thanks.

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