Creating a Boundary from Parcel

[darkman257]

Little thoughts on this.  I am looking at a large area with approximately a thousand parcels in a shp file.  The polygons of course are independent and the lines sometimes don't touch or they overlap.  I want to be able to draw a perimeter around the parcels.  What is the best way to draw a boundary?  I have tried exploding the polygons and then delete all the non essential lines and then try to create it that way but pline edit and join doesn't work and when you are looking at 10000 segments and the overlap issues or not even touching.  I am just trying to save hours if possible.  Thanks!

[Alfred.NESWADBA]

Hi,

>> The polygons of course are independent and the lines sometimes don't touch or they overlap

look about command _MAPCLEAN (>>>details<<<), that gives you some options to find such problem positions and (within a tolerance) clean them automatically.

The next step would be to create a topology, using the borders and one point-like object (block, text, point) for the parcel-id. If that fails you see where borders are not complete or where areas exist without parcel-id (that would be some small peaces from overlapping situations.

Good luck, - alfred -

[antoniovinci]

Last week I had to clean up 4800 parcels of a map: I obtained a right topology after 1.5 day of hard work.
That's because the _MAPCLEAN routine displays where are the errors, but their correction is up to you, sir.
Anyway, you might elaborate the Alfred's advice by reading here.

[olivier.eckmann]

Hi,

set SOLIDHIST to 0

comand _REGION to convert all closed polyline to REGION

command _UNION to add all region to one region (overlap and commun border are eliminated)

explode your region 

erase inner lines corresponding to gap between original polyligne

_Pedit _join to create your boundary with external remaing lines

Be careful with _UNION command with lots of objects, it can be long and crashable. If so, try to add per 100 or 200 regions.

Olivier