Questions tagged [v.clean]

v.clean is a Grass GIS algorithm which allows the user to automatically fix topology of vector maps.

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What am I doing wrong with v.clean in QGIS 3.22 LTR?

I am trying to use v.clean to fix small overlaps and gaps in a polygon dataset. However, I always get an empty output. What am I doing wrong? I've tried different thresholds but the result is always ...
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Why does Dissolve tool create little holes in the resulting polygon?

I tried to dissolve a couple of polygons and found out that it creates little holes in the Polygon (see: QGIS Dissolving and holes). I knew how to 'fill' the holes (with v.clean) but I am wondering ...
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Unable to aggregate line segments while summing values

I've a layer with multilines, overlapping to a various degrees. I need to merge/dissolve them "downwards" while summing their values for the overlapping segments. I made it to "Union&...
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Using v.clean crashes QGIS

I am working on a shapefile depicting English administrative divisions in QGIS 3.16.15. I began first by using the 'Fix geometries' tool to remove invalid geometries. Then, I used the topology editor ...
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Generating line features with "must not have dangles" constraint in QGIS

I am making line features in QGIS and sometimes, if I work inaccurate, they have dangels (loose ends). That is what I want to avoid. There are ways to detect dangles after creating a feature (topology ...
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How to automatically clean hollow lines in middle of polygons in QGIS?

I am trying to correct automatically this kind of errors. I already tried the tools v.clean (maybe I have to tune some parameters?) and correct geometries. I also tried dissolving, but since there is ...
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3 votes
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411 views

Why is v.clean not working?

I’m trying to clean the snapping errors from my line layer. I have a problem with running the tool and the outputs. During the run, many errors and warnings arise. I tried to use the tool in both UTM ...
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Fixing dangles (lines) with v.clean and "fix geometries"

I need help with fixing my two dangle-errors: there are 2 dangles on the top right and one small hole on the top-left corner. I can deduct them with the Geometry Checker, but I cannot fix it (...
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How to use v.clean in QGIS to fix polygon topology

I have QGIS 3.18 Zurich with GRASS 7.8.5 installed on my 64bit Windows machine. I have digitized 1600+ polygon boundaries that now have sliver polygons, gaps, and overlaps which I've confirmed via the ...
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  • 613
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v.clean cleaning topology

I'm doing some tests with the v.clean but getting some results that I don't really know if I am the one doing something wrong or what. As you can see in the image bellow I created 3 features, one with ...
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Problems with cleaning the topology of a shapefile using GRASS tools and snapping tools

I have a shapefile with almost 1000 polygons (each polygon representing a farm). There are a lot of topological errors (gaps/slivers and overlaps between polygons). Below is a "zoomed in" ...
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Automatically join lines by snap

After I smoothed a layer of lines I lost the connection with some vertices. Is there an automatic way to connect the various lines to avoid doing it manually? I think the best thing is to use v....
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V.Clean is not giving output In QGIS 3.14 Pi

I was trying to clean by removing sliver lines between set of polygons in my KML file. But unfortunately I am getting following error: QGIS version: 3.14.15-Pi QGIS code revision: d5114d2cfa Qt ...
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3 votes
1 answer
108 views

v.clean is stuck at 0%

So I have a layer with thousands of gaps and overlaps that I want to tidy up, but when I go to run v.clean in order to do so, it just sits there at 0%. I have no warnings or errors in the system, and ...
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R: read and clean layer with v.clean (using rgrass7)

I'm trying to execute some rgrass7 processing from R but I can't even get the first process done. I would like to clean a vector line layer. The goal here is not just to clean the topology, that's ...
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