Take the 2-minute tour ×
Geographic Information Systems Stack Exchange is a question and answer site for cartographers, geographers and GIS professionals. It's 100% free, no registration required.

Here - http://gisintelligence.wordpress.com/2011/04/19/limiting-xyz-geometry-drift/ I found the description of XY Resolution and XY Tolerance in "Arcgis World".

I have a question - my cadastral data in shapefile format have accuracy 1 cm. So, if I want to work with my data in Arcgis File Geodatabase I should use XY Tolerance 0,01 m and XY resolution 0,001 m ( http://goo.gl/uqDrG

  • is that ok? I mean - that values are proper for topology matters and so on?

Thanks for answer

share|improve this question
add comment

1 Answer 1

x,y tolerance

Your data has an accuray of 1 cm. With this accuray I would not use a x,y tolerance of 1 cm. During feature processing operations coordinates that fall within the x,y tolerance will snap to the same shared coordinate location. The maximum distance a coordinate could move to its new location is the square root of 2 times the x,y tolerance. If you use a x,y tolerance of 1 cm the maximum distance a coordinate could move is 1.4 cm. So the coordinates will move more (1.4 cm) than the accuray (1.0 cm) of our data. This image from esri help shows how coordintes will move:

tolerance

I would use a tolerance of 0.1 cm.

resolution

The x,y tolerance should be coarser than the resolution. In ArcGIS the default value esri uses for the x,y tolerance is 10 times x,y resolution. If you use a tolerance of 0.1 cm you shold use a resulution of 0.01 cm.

(It is possible to use every value as tolerance and resolution (e.g. 0.5, 0.12345, 0.99 ...). But I like to use a resolution of 1.0, 0.1, 0.01, 0.001 ... This makes it more easier that the resulution grid of different projects (with different resolutions) fits together.)

Summary: I would use a x,y tolerance of 0.001 m and a resolution of 0.0001 m.

share|improve this answer
    
Thanks for reply –  Piotrek Jan 24 '13 at 14:57
    
@ piotrek: does the answer solves your question? Then you can mark the answer as "accepted" - see here. Or do you still need help? –  Jens Jan 25 '13 at 12:27
    
Hi - I clicked button - "Was this post useful to you? Yes" - sorry, I'm new and I don't know about all rules here. Yes, Your answer was great, thanks! –  Piotrek Jan 26 '13 at 15:25
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.