How about this solution:
1. Make a new table containing a copy of your paddocks table structure.
Let's call it ZoneVoronoi
2. Open this this, add it to a map and make it editable
3. Now we need another copy of the paddocks table, Let's call it ZonePoints
3. Now we have to convert the regions in ZonePoints to points to be able to
create voronoi regions using these:
a. Open the MapBasic window and enter the line below followed by
Enter
Update ZonePoints set OBJ = CreatePoint(CentroidX(OBJ),
CentroidY(OBJ))
4. Now select all records in the ZonePoints table (this can be made easily
by selecting a single record, pushing the Invert Selection and then
reselecting the single record again while holding down the Shift key
5. Now we want to create voronoi regions using these points and insert these
regions into the ZoneVoronoi
6. Now we have to delete those parts of these voronoi regions that are
within an existing paddock:
- Select all the voronoi regions
- Set these to target objects
- Select all existing paddocks
- Use the menu item Objects > Erase to erase overlapping areas
7. Now we have to insert the existing paddocks in the ZoneVoronoi. Select
all paddocks, Use the keys CTRL+C to copy and CTRL+V to insert into
ZoneVoronoi.
8. And finally we want to combine the paddocks that have the same zone id
into a new table called Zones
- Choose Table Combine Objects using column
- Choose ZoneVoronoi as input table, your zone id column as column
and choose the insert the result into a new table
- Make sure this new table at least holds the column for the zone id
and tell MapInfo to read this value from the column holding this value in
the ZoneVoronoi table.
Et voila !
HTH,
Peter Horsb�ll M�ller
GIS Developer
Geographical Information & IT
COWI A/S
Rug�rdsvej 55
DK-5000 Odense
Denmark
Tel +45 6313 5013
Direct +45 6313 5008
Mob +45 5156 1045
Fax +45 6313 5090
E-mail [EMAIL PROTECTED]
http://www.cowi.dk
COWI GIS konference afvikles i dagene d. 2.-3. september.
Se yderligere oplysninger p� www.cowi.dk/Div04/Profiles/nyheder.asp
> -----Original Message-----
> From: Robert Crossley [mailto:[EMAIL PROTECTED]
> Sent: Thursday, July 10, 2003 2:49 AM
> To: MapInfo List
> Subject: MI-L Making zones.
>
>
> Hi all,
>
> I have a file with about 1500 farms composed of about 60000 paddocks,
> usually separated spatially. These are grouped into 47
> reporting zones.
>
> Is there a function or program that can create a map of those
> zones. I
> want to create a table that has spatial representations of
> those zones,
> with the spatial objects contiguous - and would prefer not to have to
> digitise those boundaries.
>
> When I simply do a merge using column, I get the same
> separate paddock
> outlines (except those where the paddocks touch), with 47
> complex objects,
> and a 4MB file.
>
> Convex Hull makes overlapping regions.
>
> Veroni ignores the extent of the paddocks when creating its objects.
>
> Buffering takes forever, and overlaps neighbouring zones anyway.
>
> What I really want is veroni polygons that are created using
> regions rather
> than points.
>
> TIA
>
> R
>
> --
>
> Robert Crossley Agtrix P/L
> 9 Short St
> New Brighton 2483
> Far Southern Queensland
> AUSTRALIA
>
> P: 02 6680 1309
> F: New Connection
> M: 0419 718 642
> E: [EMAIL PROTECTED]
>
> ---------------------------------------------------------------------
> List hosting provided by Directions Magazine |
> www.directionsmag.com | To unsubscribe, e-mail:
> [EMAIL PROTECTED]
> For additional commands, e-mail:
> [EMAIL PROTECTED]
> Message number: 7568
>
---------------------------------------------------------------------
List hosting provided by Directions Magazine | www.directionsmag.com |
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
Message number: 7571
