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Questions tagged [self-intersection]

14 questions
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3 answers

Automatically fixing ring self-intersections in shp2pgsql

We're importing a whole bunch of ArcGIS shapefiles into PostGIS, converted on the fly with shp2pgsql. Problem is, if the shapefiles have any ring self-intersections, the import chokes: NOTICE: Ring Self-intersection at or near point -80.1338…
lambshaanxy
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Using Opencv and C++ to find areas of very small objects, possibly self-intersecting

How do I calculate areas of very small objects, sometimes 2 pixels in area? MATLAB's regionprops() seems to do this well, and will return values of even 1 for a point. I've read widely on this issue and everyone seems to caution against…
darel
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Google Maps Polygons self intersecting detection

I'm trying to implement a polygon self intersection algorithm from Google Maps API V3 polygons. The goal is just to detect if yes or no, a simple polygon drawn by the user is self crossing. I have found this very interesting link, but it assumes…
AlexB
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Openlayers 6: How does openlayers handle broken geometries?

Sorry if I am being an idiot but I can't locate this information. If I force a WFS service to provide bad vector geometries (vector source, vector layer) how will openlayers handle this. This may be non OGC Compliance, self intersecting polygon,…
Phish
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shapely object.buffer(0) return a empty polygon(coordinates:[]),and discard the main polygon

There are self-intersect polygons in my geojson files.So I used the shapely lib to fix it. The code is like this: clean = geom.buffer(0) Most of the polygons have been processed properly,but there are still few polygons returned empty,which…
han
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Why is Meshlab identifying self-intersecting faces incorrectly?

meshlab occassionally finds spurious self-intersections that don't seem to be correct - see this minimal example of just two faces. meshlab identifies the faces as self-intersecting. If I save the file as an ascii stl, the file no longer shows to be…
James
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Finding Self-Intersections in Leaflet polygons using JSTS Library

I'm using Mapbox with Leaflet Draw, and I would like to avoid self-intersecting polygons. I can already specify to not allow intersections while creating the draw control, but it only works when I use the control to create a new polygon. However, if…
Raj
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Deleting a self intersecting face by its number

I have a mesh that I import to the Meshlab and simplify, clean, and reconstruct the mesh. I export the final mesh from meshlab and import into finite element software (COMSOL). While importing, I received the error message of "Self intersecting…
Hamed Rahimi
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1 answer

find the lines cross while draw free path using QPainterPath

I'm implementing the free-form style drawing for drawing a free path using the mouse press and move with Qpainter QPainterpath Now i have to detect when exactly the drawn path crossed or intersects with the other. how i can identify when the lines…
Wagmare
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google maps api v3 add new polygon vertices without crossover or self-intersecting

Seems like this one maybe too hard even for the gurus so I will try and re-word it to try and get some response: I am trying to add a vertex or vertices to an existing polygon intelligently without crossovers or self-intersection but all I can find…
Optorock
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How to use `polyclip::polysimplify` on a polygon

I am trying to get rid of intersections in state polygons from ggplot2 library("ggplot2") states <-…
Dylan_Gomes
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Polyline self-intersection

I am writing code to determine if a polyline is self-intersecting or not. If at least two links of a polyline intersect (at their internal points), it is called self-intersecting. To begin with, I write a function to determine the intersection of…
Murad Mammadzada
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Is there an oracle spatial function for finding self-intersecting linestrings?

I need to find all self-intersecting linestrings in table. SDO_GEOM.VALIDATE_GEOMETRY_WITH_CONTEXT finds only self-intersecting polygons, because self-intersecting linestrings are allowed. Any ideas?
Catherine
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boost self intersections, doesn't find the colinear segments intersecting

i'm trying to find intersections in a polygon. specifically i'm interested in collinear intersections, where two segments just lie on top of each other and intersect on all the common part. i think it has something to do with the policy , but not…
Sergey Benkovitch
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