Questions tagged [ring]

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Making ring buffers (donuts) in Google Earth Engine

I am trying to generate multiple buffers around a layer that represents cities (FeatureCollection). Use the following code to create the buffers: // Function to create buffers of different sizes in ...
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118 views

QGIS 3.10 Add ring to shapefile - “Unknown error”

I have a polygon shapefile layer with some overlapping polygons, styled using categorised labelling with different styles layered on top of the others. I would normally use the "Add ring" tool to draw ...
2
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1answer
136 views

Automatic filling of rings with additional polygons in QGIS

I have a large layer with a couple of thousand polygons mapping inland waterbodies. A lot of these contain rings, mapping islands. I would like to count the number of islands and do some statistics ...
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1answer
56 views

QGIS Dissolve tool erroneously fills rings in polygons

I have a shapefile layer with >27,000 polygons. I want to dissolve these together to create a footprint layer. The Dissolve tool works fairly well, but it has filled in what should be rings in the new ...
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1answer
134 views

Polygon node order will not correct [duplicate]

I've got a few polygons (they were previously one multipolygon) which seem to insist on having an anticlockwise node order. As such, when running through various operations in SQL, they throw out the ...
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0answers
83 views

How to enable tracing in QGIS 3 beyond applications for adding polygon purposes?

I have used the enable tracing feature in QGIS 3 to create new polygons (Add polygon feature), and it works very well. However, i have not been able to use it for other purposes beyond that, for ...
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3answers
1k views

Creating polygon from hole in QGIS?

I work with this polygon and try to find a way to create a new polygon from the empty gap (not distinguish it) in the middle of the polygon. I succeed to do it with a "Difference" tool but used with ...
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2answers
2k views

Add ring and Fill Ring error: could not add ring since the inserted Ring is not contained in a feature

I'm new to QGIS and am struggling a bit, I'm using the 2.18 version on a Mac OSX Yosemite. I'm trying to add a ring to create a geological map, I was successful for most of the map, but suddenly it ...
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1answer
430 views

Polygon holes/rings are showing up as polygons in QGIS

I am having an issue in both QGIS 2.18.17 and QGIS 3.0.1. It is to do with holes/rings. Where there are meant to be holes/rings, actual polygons are showing, these are effectively coming in as ...
7
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1answer
4k views

How to fix polygon with ring self intersection in QGIS?

When I polygonize a raster, I very often have 'pixels' holes/interior ring that touche exterior ring. Example : POLYGON((5 0, 10 0, 10 10, 0 10, 0 0, 5 0, 3 3, 5 6, 7 3, 5 0)) It's defined as an ...
6
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2answers
233 views

Is there any tool in QGIS to select and translate an inner ring without altering it nor the rest of the polygon?

I want to highlight the cloudfree pixels of a satellite image of which both of it with the cloudmask had been imported and reprojected from another GIS software. Because of the reprojection, my ...
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0answers
113 views

arcobjects modify vertices coordinate in both interior ring and exterior ring

I have a multiple parts polygon and I want to move all vertices of this polygon. I use exteriorRingPointCollection and interiorRingPointCollection to get all vertices. But I cannot get the result I ...
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0answers
90 views

Incorrect results returning from st_distance_spheroid query

Given a routable network table constructed by completing the guide at http://anitagraser.com/2011/02/07/a-beginners-guide-to-pgrouting/, how can I get an accurate list of all roads that are within a ...
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3answers
1k views

Creating rings from existing polygons using QGIS?

I have been given a shapefile from a client that features pivots, yet they were recorded as 10 circles overlapping. The software my company uses requires that these polygons be rings that don't ...
4
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1answer
95 views

Geoprocessing tools fail though CRS same, prj-file ok, edit mode off, topology valid, etc

For my layers none of the QGIS geoproccesing tools (difference, intersection, etc. all give empty attribute tables) work, though I've checked for all (?) error sources (as in the title). Then I tried ...
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1answer
5k views

How to fill in ring polygon in QGIS?

I created a polygon which covers a park. But I want to distinguish some small buildings located inside the park. Consequently, I want to distinguish them and use them as independent patches inside the ...