Hi: You could create a formula field with a single value, e.g. 1. Use Merge by Value to merge all areas into a single polygon. Use Tools-Geographic Utilities-Line/Area Conversion to convert the merged areas into lines. Use Tools-Geographic Utilities-Line/Area Conversion to convert the lines back into areas.
Maptitude Mapping Software <http://www.caliper.com> Group Moderator --- In [email protected], Reinaldo Paul Pérez Machado <rpmgis@...> wrote: > > /*Hi guys, > > I would very much appreciate your advice here. I have to perform a merge > by value operation over a polygon geographic database with more than > 300000 parcel records. In the first attached image > (MergeByValueProblem1.png), I have place a small sample to show what is > all about. As you can see, every single polygon is an individual area > with full topology and corresponding ID. I have to merge all clustered > or contiguous polygons (sharing at least one border) into a new one, > that is dissolving the internal lines to produce a bigger resulting > area. I would normally use the Merge by Value command, but the problem > here is that only the clustered polygons should be merged and the > resulting polygons should have a individual new ID (just in case that > some merging was produced), area and perimeter, and all previously > isolated areas should remain like that. In the above described example > the successful operation should ends up with just 7 polygons (see the > other annexed sample, MergeByValueProblem2.png). > > As I have said the real set is simply too big to do this by hand, so I > would have to find some kind of automation on the process. As an > additional information there are regions (see the black thick line) that > encloses subsets of this small parcels so it is possible to perform an > attribute tagging in order to identify which parcels belong to each > region or "districts" but again the resulting standard merge by value > operation would result on a non desired result. > > Thanks in advance for any aid you could provide on this matter. Cheers, > > Reinaldo*/ >
