Question

Why the Clipper transformer is too slow?

  • 24 January 2018
  • 3 replies
  • 21 views

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Hello everyone,

I need the [B] (Green) areas, the administrative Areas outside of road Buffer Areas. Be precise, I need an area which have no Road.

Therefore, I used:

Bufferer -> Generalizer -> Clipper ("Clippers First" to the Clipper Type parameter in the Clipper)->

Buffer areas are in Clipper port and the administrative boundary areas in the Clippee port and output is Esri Geodatabase (File Geodb API).

Unfortunately, the Clippers is too slow. After 14 hours, it finished only (clipping group 16985 / 33079)

I have total 60001975 buffer road. How can I improve the speed of the Clipper and get my desirable output.

Thanks


3 replies

Userlevel 4
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With over 60 million clipper features it is going to take a long time. There's a few things you can try in order to speed this up.

  1. You mention you set the Clipper to "Clippers First", that's great and indeed a setting you should use for large volumes of data. However, make sure your roads are also read first. Drag them up in the Navigator panel so they're all the way at the top.
  2. Potentially joining the roads before buffering them will cut down on the number of clipper features. Or dissolving the buffers once you've created them. I would recommend to do that as a separate step if it's at all possible. So a workspace to create the simplified buffers and then a second one to do the actual clipping.
  3. I would also highly recommend trying this out with a smaller subset of data to see if you can win any more time anywhere.

Without seeing your workspace and data it's hard to come up with detailed advice but hopefully this will help you further.

Userlevel 4

With over 60 million clipper features it is going to take a long time. There's a few things you can try in order to speed this up.

  1. You mention you set the Clipper to "Clippers First", that's great and indeed a setting you should use for large volumes of data. However, make sure your roads are also read first. Drag them up in the Navigator panel so they're all the way at the top.
  2. Potentially joining the roads before buffering them will cut down on the number of clipper features. Or dissolving the buffers once you've created them. I would recommend to do that as a separate step if it's at all possible. So a workspace to create the simplified buffers and then a second one to do the actual clipping.
  3. I would also highly recommend trying this out with a smaller subset of data to see if you can win any more time anywhere.

Without seeing your workspace and data it's hard to come up with detailed advice but hopefully this will help you further.

I agree, these are some great tips. Definitely try dissolving the roads (point 2) and, if possible, generalize them as much as possible (point 3 is your friend to tune this).
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Hi! david_r redgeographics takashi

When I use Generalizer-> Bufferer ->dissolver then shows this error and all dissolve area comes on the rejected port of Clipper and out put it written only the administrative boundary.

ClipperVector(ClippingFactory) Extra clipping feature encountered and ignored

ClipperSolid(SolidIntersectionFactory) No clipper supplied for group,all clipees will be treated as OUTSIDE

Do you have any suggestions?

 

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