Questions tagged [self-intersection]
A self-intersecting polygon is where the boundary (edge) crosses over itself.
58 questions
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Find intersection points of lines in the same shapefile where no vertices exists in QGIS
I've a very large linear shapefile wich represents pipes.
I need to determine the position of every intersection between lines in this shape, only where no vertices already exists (I think with 0,-1 ...
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QGIS Single sided buffer value of specific area and line length on 90 degrees lines
I need to Single Sided Buffer a specific surface based on a line length, on QGIS.
Example:
line length: 60.367 meters.
area needed from single sided buffer: 452.4 square meters.
theoretic Single ...
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PostGIS tesselation invalidating polyhedralsurfaces
We are trying to visualise prefabricated concrete elements.
These elements are exported in an ifc format. https://technical.buildingsmart.org/standards/ifc/ifc-formats/
We have already been able to ...
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PostGIS not finding self-intersections
According to this link, ST_IsValid should return self-intersections.
However, using the following WKT, I get that the following line is valid:
SELECT ST_IsValid(ST_GeomFromText('MultiLineString ((8....
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Eliminate Selected Polygons in QGIS creates an incompatible GeometryCollection
I have a multipart shape file created from a GeoJSON. The original geoJSON is from the Vermont Open Geodata Portal, so a lot of the polygons have errors and overlaps.
To fix the overlaps, after I ...
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Self-intersections from geoprocessing in QGIS but detected via digitizing validity checks
I have performed a set of geoprocessing tasks to produce a polygon output. The polygon output contains - what I would consider an invalid set of vertexes and as such, an invalid geometry. (see screen ...
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R: Error in CPL_geos_op2(op, x, y) : Evaluation error: TopologyException: Input geom 1 is invalid: Self-intersection at
I am new to using CRS on R and thus am confused and have the following question:
I have two .shp files from -
https://github.com/HindustanTimesLabs/shapefiles/blob/master/city/delhi/ward/delhi_ward....
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Mapping self-intersections of a transformed LineString
I’m using shapely to solve a problem in physic. My problem can be represented in 2D with a LineString. In order to solve my problem I need to :
Apply a transformation to the original LineString
Find ...
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4
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1
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QGIS does not find self intersections, but ArcGIS Pro does
I am working on a project that includes preparation of a series of polygon shapefiles that need to go through an official geometry/topology check-up before final submission. This official check-up ...
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How to remove remove self-intersections(?) from a river network line
I am working with a new global-scale river network that splits around large islands (blue lines).
I will be working with the river network in Google Earth Engine and have completed some prior vector ...
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Reproject valid features returns geomety error with PostGIS
PostGIS3.2, PostgreSQL 13
I have a table with multipolygons.
There is a constraint CHECK (st_isvalid(geom)) on it.
Run a query with st_ivalid(geom) returns no error fortunately !
When I try to ...
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Python `shapely` - split a complex line at self-intersections
Description
Sum-up
When splitting a complex line - let's say with a single "loop" - shapely.ops.split applied at the self-intersection point returns two lines where I would expect three ...
- 151
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How to prevent self-intersection when using Intersect tool in ArcGIS?
When using the Intersect tool in ArcGIS (Desktop 10.8): I have two inputs, a polyline FC and a polygon FC. I want to get the intersection of each polyline feature with the polygon features, so the ...
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PostGIS: Is it safe to always call ST_MakeValid to "fix" geography polygons?
I have a GeoJSON file with latlong polygons for the US state of New Mexico. I've loaded them into Postgres, using the geography column type.
For some of the polygons, I get an error when calling ...
- 163
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Self-crossing/intersecting polygon in QGIS that tools identifies them as valid
I am using QGIS 3.14 long term version. I need to identify these polygons that are self-crossing.
Here are the tools I have tried
SAGA's "Polygon self-intersect";
check validity from ...
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