8 replies to this topic

[angel.spatial]

Hello all,

I wanted to know if there is a way to remove duplicates specifically in ArcGSI 9.2. I have a file that was merged long ago (not by me) and there is a duplicate of EVERY polygon (over 50000). I need to know how to go in and automatically delete any duplicates. I tried TypeConvert, but it will not install (of course). Any direction would be greatly appreciated!

Thanks,

angel

[Hans van der Maarel]

I wanted to know if there is a way to remove duplicates specifically in ArcGSI 9.2. I have a file that was merged long ago (not by me) and there is a duplicate of EVERY polygon (over 50000). I need to know how to go in and automatically delete any duplicates. I tried TypeConvert, but it will not install (of course). Any direction would be greatly appreciated!

If you want, I can run it through FME for you. Just PM or email me privately if you're interested.

[gregory]

Hi,
What about using dissolve with AREA field?
If you set the declimals of that field enough to every polygon be not identical but just the same as its copy then runing dissolve should double resize the number of your records.. Just an idea.
You should easily got what are you asking for using "Remove Duplicates" function in manifold.

regards
Gregory

[A. Fenix]

Hello Angel,

I found this script on ESRI's support site that may also do the trick:

http://arcscripts.es....asp?dbid=14811

I haven't used it personally, but it certainly sounds like it would do the trick.

Good Luck!

Analisa

[angel.spatial]

Wow I love this forum! You guys are so helpful.

I will try the script and see how it goes. I wish we used FME and Manifold here, that would make certain processes much easier. I will let you know how it goes!

angel

[angel.spatial]

I tried the script and it didn't work. It cannot sort through so many polygons.

What about just automatically checking for overlaps within one layer? I know that you can do this with topology, but you cannot tell it to merge or just take the first one for ALL of them at once. Is there a tool that I don't know about.

I tried the dissolve tool and nothing seems to be happening. I need all of my attributes in the resulting table so I selected all attributes to dissolve by....was this wrong?

angel

[gregory]

I just tested merging using dissolve by area in manifold and it did the trick. The two individual records that you want to merge are identical so you want miss any fields just dissolving by AREA field (and only that). Using AREA came to my mind cose it's really hard to find in nature two shapes with identicall area (so epand declimals in area field as much as you can). Note that is going to work while the area of the polygons you're trying to merge will be identical just for a shape and its copy, otherwise you will not get exaclly the half of records but some more shapes will be merged into a single shape. But in that case you should try to run with something like 'decompose' in manifold - http://www.manifold....m_decompose.htm. You will have to look for such kind of tool in arcgis.

The second option. Split you shapefile into some smaller parts and then try to run the script suggested by Analisia. Maybe it will handle it.

regards
Gregory

[angel.spatial]

Thanks to everyone for all the help!

Here is what I have ultimately come up with...I decided to aggregate features in the single shapefile and that seemed to do what I need.

I will also try the other methods (just so I can learn) and see how they go. I will look for the decompose and play more with the dissolve on smaller shapefiles.

Thanks again - angel

[pfyfield]

Dissolve by area is the way to go (unless there's a feature id that is the same for both of the duplicate polygons- then use that).

If you need to retain all your attributes save a copy of the dbf file and join it back to the output of your dissolve using the area field. That ought to work.