Labeling based on Location

Question

Hello,

I have a map containing about 150 parcels.  I would like to label the parcels based upon their locations, with 1 being the Northwestern-most parcel and 150 being the Southeastern-most.  Unfortunately I do not have a field that corresponds to that scheme.  Is there an automated solution to this type of problem, or will I be forced to manually populate a new field?

Thanks in advance.

KimOllivier · Answer

There is a better way to sort points for labelling. The technique uses a Peano curve to sort the points into a snakes and ladders type of route where the next number is always near the last. This is similar to the way that we used to number labels on polygons when we used to digitise by hand!

The Peano Curve is an option on the ArcGIS 10 sort (data management) tool. It basically comes up with a single index for the x,y pairs that is a very useful figure to sort a point cloud so that you can easily find any point if they are sequentially numbered.

PaulBoehnlein · Answer

I've just revisited this workflow and the Sort tool from 10 works well.

RichardFairhurst · Answer

At ArcGIS 10 there is a sort tool that can do spatial sorts, but it currently requires an ArcInfo licence.  Probably both of those things don't help you at this point, but keep it in mind.  Still wiht an Y / X field pair sort you should be able to accomplish something like the Upper Right, Upper Left, Lower Right, and Upper Left sorts.  Reversing the X and Y order would give priority to east/west movement over north/south movement.

I have not seen the results of the ArcGIS 10 tool myself, so I cannot be sure they don't have a fancier algorithm under the hood.  They also have a APEANO option that I do not fully understand.

Anyway, with a set of X / Y fields you could previsualize the sort in a tableview and walk through the features to see if the order did what you wanted with any of the above sort orders.