How to create a unigue IDs to Near_Dist values

[ABDALLAMOHAMED]

Hello all...I need to derive connectivity between  polygons, That is, to show connectivity between polygons of similar near distances.For example polygons with IDs 1, 3,6, 8 have the same near distance, and I can give all of them one unique ID, say 1, and then go to the next polygons with same near distances and do the same, and so on and so forth. Any help..appreciated..
Thanks!
ABDALLA

[DanLee]

Just want to add a note here:

Grouping features by numerical field, such as NEAR_DIST used in this scenario, is sensitive to the precision of the decimal numbers. You might want to round up the values to a number of decimal digits that is significant enough for the analysis to avoid getting too many unique groups or IDs.

[DanLee]

And another note:

If you have ArcGIS 10, you can use the ModelBuilder Iterator tool, Iterate Feature Selection or Iterate Row Selection, to loop through selections defined by the Group By Field, in the case above this would be NEAR_DIST. Then for each selection use Calculate Field with the expression:  %n%+1  to assign the unique iteration value starting with 1 in the added field.  It is pretty simple.

[ABDALLAMOHAMED]

Dan.. I have ArcGIS 10, but I couldn't find ModelBuilder Iterator tool. I would like to give it a try. Any hint on where to find such tool..Thanks a lot..
ABDALLA

[DanLee · Accepted solution]

Sure. They are ModelBuilder-only tools, not in the toolboxes. You should be able to search the Help system by "iterators". Here I quote the description from the Help topic "Accessing iterators in ModelBuilder":

"There are two ways to access iterators in ModelBuilder: through the Insert menu or from the shortcut menu (right-click in open space in the model).

- Click Insert > Iterators and choose an iterator to add to the model.
- Right-click in open space in the model, click Iterators, then choose the iterator to add to the model."

Hope you find them helpful.

[ABDALLAMOHAMED]

Dan.. I found the Iterators..
Thanks a lot..
ABDALLA