Where features overlap

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27 views

ST_Intersection between MultiPolygon tables leads to gaps, missing intersections

I am trying to intersect two MultiPolygon tables, which are in the same UTM projection, and calculate the area of their intersections. I am getting some surprising results when I examine the ...
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0answers
10 views

PostGIS Street Intersection Autocomplete with full text search

What I'm attempting to do is create a custom autocomplete for addresses, road intersections, POI's, etc. For now we are going to using Mapbox GL (we'll be creating a custom map at a later phase), ...
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2answers
3k views

OGR Layer Intersection

I am using what I would describe as the most primitive method of doing intersection with OGR. The short script below describes how I do it. Is there a best way of doing this? from osgeo import ...
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2answers
204 views

Using st_intersects caused mismatch when a marking (tagging) shape marked a polygon overlapping only on the edge

I have accidentally marked a landshape as being tagged "CU GO-M" because it seems to share an edge with a tagshape for "CU GO-M" but nothing else. I used the st_intersects method to join these shapes ...
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1answer
194 views

How to connect centroids of lines sharing the same intersection in QGIS?

I'm looking for a big help to accomplish the following task: I have this street network of the center of Turin (IT), composed by lines representing streets, and black points representing ...
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2answers
509 views

How to intersect FeatureCollections in turf.js efficiently?

I've been playing around with turf.js and I'd like to use turf.intersect to intersect two datasets. My raw data are two polygon shape files so I converted them to geojson. I then tried to use ...
3
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0answers
32 views

QgsSpatialIndex partial or complete overlap

I'm working on adding some functonality to a QGIS plugin. It currently uses a QgsSpatialIndex to efficiently compute whether the features of a vector layer intersect (potentially millions) of ...
4
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1answer
67 views

Find all intersections of a LineString and a Polygon and the order in which it intersects it

I would like to find out all intersections of a LineString (River) through Polygons (Municipalities). I would like to list the order of municipalities which the river crosses, using linear ...
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0answers
25 views

How to collect values from iterated intersections, in ModelBuilder

I have a points feature class which I am intersecting with a number of polygon feature classes, one at a time (i.e. points AND polygons1, points AND polygons2, etc...). Each time I do an ...
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0answers
12 views

Intersect Iso_rectangle_2 with Polygon_2 where Polygon_2 uses Projection_traits_xy_3

I have a set of [Point_3][2] that constitute a Polygon_2 using the Projection_traits_xy_3 typedef CGAL::Exact_predicates_inexact_constructions_kernel K; typedef CGAL::Projection_traits_xy_3<K> ...
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1answer
187 views

QGIS 2.6 simplify a road network to obtain the intersections

In QGIS 2.6.1 in Ubuntu, I want to measure the density of block in this city (FYI my final aim is to measure the TOD level). I have the road network from French national IGN dataset BDTopo. I have ...
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0answers
45 views

Calculating area of intersection of polygon to another layer in ArcGIS for Desktop?

I am very new to GIS, especially ArcGIS. I am currently using ArcGIS 10.2, and I have 2 layer, namely the purple feature map(this layer is an import from arcgis online, it doesn't seems to be an ...
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2answers
198 views

Intersection point of polygon and the line created by two points ArcPy

I have polygon layer. I selected the most distant vertex from centroid (picture: point A). (How to do that is in the answer here: Select the most distant vertex from polygon's centroid using ...
3
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1answer
40 views

ArcGIS find all polygons that intersect with more that one polygon from another layer

I have two layers with polygons. I want to find those polygons from first layer that intersect with more that 1 polygon from second layer and find those intersected polygons ID numbers: 1 from first ...
4
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0answers
41 views

Why won't my points (that I created by intersection) won't intersect with the geometry they've been created from?

I created a set of points by intersecting a linestring layer with the boundary of a multipolygon layer like this: CREATE TABLE freiraumkataster_grenze AS SELECT gid, ...
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0answers
15 views

Subset of spatial data causes slow SQL Spatial STIntersects

I've been having an issue were a specific subset of data causes an SQL spatial intersect to run extremely slowly. I am running sets of 1000 points against a subset of polygon layer to be intersected. ...
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4answers
1k views

Produce a list of polygons that a line crosses

I have a polyline feature class and a polygon feature class. What I want to do is add a field to the lines that lists all polygons that touch the line. This is effectively performing a ...
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1answer
344 views

Generating report or table for buffer zone using ArcGIS Desktop?

I have a polygon feature class. I create a buffer for this feature with a distance being 2 km. Now the buffer output intersect with features of the original polygon. So say for instance from the ...
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3answers
4k views

Intersect (analysis) of polygons generating empty output

I have previously asked a question on determining the area of polygons with another polygon boundary. Determining the area of each polygon within a polygon boundary? I came to the conculsion that ...
4
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1answer
2k views

Intersecting two polylines using ArcObjects?

I have two polylines and would like to find the intersection(s) using ArcObjects / VB.NET. I'm using the following code: Dim topoOp As ITopologicalOperator = TryCast(pTestPoly2, ...
2
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0answers
24 views

Intersect, Spatial Join?: One Line crossing Multiple Polygons, assigned wrong attribute

I am looking for any possible solutions to a problem I am encountering with ArcGIS. I am using census block groups (CBG) to assign streets an income level value based on their location within the ...
3
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1answer
43 views

Rotate symbols perpendicular to line angle (QGIS)

I have lines representing curving streams and want to angle symbols at various points on the streams so that they are perpendicular to the angle in their particular locations. What QGIS seems to do ...
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1answer
263 views

Using M 'Measure' value in SQL Server 2008

MS Sql Server 2008 geometry type supports adding Z and M values to geometry objects, including linestrings. However, I cannot find any way to make use of these values, since methods such as ...
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1answer
70 views

Problem intersecting shapefiles with OGR in Python

I'm trying to move from ArcPy for geoprocessing. After searching some posts, I found this solution using the GDAL/OGR Python bindings: Intersect Shapefiles using Shapely My code is the following: ...
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6answers
4k views

PostGIS: Select features that do NOT intersect

This seems to me like such a simple question (and it probably is) yet I cannot seem to find an example that gives me the answer. Using PostGIS, I just want to select points that fall outside of ...
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0answers
14 views

How to Find Source and target using STBuffer And STIntersects in SQL Server?

I am using this query to find the source and target from Routes table, but it's not getting the correct result SELECT TOP 1 a.target FROM Routes a WHERE ...
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1answer
25 views

Tabular Intersection producing Empty Output Why?

I am trying to run a Tabular Intersection on ArcGIS 10.2.2 between a 1000m buffer and a forest layer to establish the percentage cover and total area of trees within the buffer areas. Everytime I run ...
2
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1answer
221 views

Intersection of two Raster objects

I have two raster objects r1 (in grey and green) and r2 (in pink) that I want to intersect with R. I tried with the R function intersect from the raster package but it only intersect the extent of the ...
4
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2answers
59 views

What is the correct syntax for the geometry object's “intersect” method in ArcPy?

I'm building a script that utilizes the intersect method of the geometry class so that I can run an intersect analysis on individual polygons within a feature class. As stated here, "intersect ...
4
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1answer
179 views

Intersecting overlapping polylines using ArcGIS for Desktop?

I have 4 multipart polyline shapefiles (download a sample dataset here). The geometries are identical, except for the length of segments in each shapefile. They represent 4 variables describing an ...
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0answers
25 views

python 2 polygon intersection

I have slope values derived from a DEM which I reclassified into NoDATA and vaules which I need. Then I made a polygon from this raster. I need to do intersection or something like that with the ...
0
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1answer
30 views

Intersect elevation interpolated from CAD file in ArcGIS

I have two datasets - contours and vector (water, roads,...) Vector layers were used as breaklines to generate the contours. Then the contours were generalized a bit. For quality check I need to ...
7
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1answer
205 views

What is the difference between Spatial predicates “Covers” and “Contains”?

I try to understand the Spatial predicates of the DE-9IM Intersection matrix. I don't get the difference between predicates Covers (respective CoveredBy) and Contains (resp. Within). I try to draw ...
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0answers
20 views

Using modelbuilder to calculate different areas of overlap over time?

Been looking all over the place for a solution to this and nothing’s turned up, so I thought I’d ask directly. I am looking to build a model that calculates the total area of timber harvest within ...
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3answers
95 views

Iterating Intersect_analysis over polygon shapefile using ArcPy?

I am using ArcGIS 10.3.1 for Desktop and I have two shapefiles: A set of stream (vector line) data A fishnet of polygons I want to know, for each polygon in that fishnet, what the total length of ...
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0answers
40 views

Intersect using Open Source GIS [duplicate]

I have a CSV containing user locations (has lat, long, userid, timestamp). I have a countries shapefile (has country name, geometry - got this from thematicmapping.org). I am trying to append a ...
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1answer
550 views

Creating point to lines intersection in QGIS?

I have two line layers, and I want to create a point where they cross each other. How can I solve it in Qgis?
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3answers
58 views

Intersection of 2 Linestrings (not interpolated)

I am struggling with a query in POSTGIS I want to find linestring geometries where the geometries are containing the same point. I don't want to calculate the intersection points. I only want to ...
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0answers
36 views

Using Python Opensource Libraries to check users who visited a store [closed]

I have a few files with location information: 1) User Lat Long Pings in Parquet Files (can be converted to CSV) format - this contains userid, timestamp, lat and lon 2) US County/State Shapefile 3) ...
2
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1answer
41 views

QGIS and intersections

I have MultiLineString geometry data from an ESRI shapefile. I also have a polygon (region) that I have created in QGIS using the drawing tools. When I attempt to find the intersection between the ...
5
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3answers
224 views

How to fix thousands of small overlapping polygons?

I'm using ArcMap 10.3. I have a layer of different land use types. I found out that many polygons overlap each other and as a result the same polygon have two different land use types. Thanks to ...
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2answers
63 views

OL3 GeoJSON vs. turf GeoJSON

I am using OL3 and I try to inspect whether two lines are intersecting or not using turf. I used GeoJSON in OL3 and fed the lines into the intersect() in turf but I get Unknown GeoJSON type. here is ...
5
votes
1answer
2k views

Calculating forest cover within buffer that overlaps with other buffers?

I'm new to ArcGIS. I have a layer showing forest cover in a landscape. I'm trying to create a 5km buffer around every forest patch in the landscape and then calculate the amount of forest within ...
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0answers
44 views

Why does QGIS only intersect one part of the layer?

I have a QGIS layer with information about administrative boundaries at sub-municipality level. I want to extract only land area in each sub-municipality using information from another layer. I've ...
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2answers
70 views

Where is the drawn feature when the drawend is triggered in OL3

I have written a piece of code to check if the drawn line is intersecting other lines in the vector layer. If so, then the line should be split and new lines should be added to the layer. here is my ...
1
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1answer
69 views

How to select overlapping/non-overlapping polygons from a single shapfile in QGIS?

I have a shapefile with a series of polygons, some of which intersect each other and some that don't. I want to select only those that do not overlap with any other polygon. I've tried the Select by ...
2
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1answer
349 views

How to intersect more than two layers? Is there a quick way?

We have three layers, income, obesity and fast food restaurants for England and we wanted to find districts where they all intercepted. So we did a combination of two layers at a time to find where ...
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0answers
29 views

Detecting features intersecting with Profile Line using ArcGIS for Desktop?

I am using ArcGIS' (10.2) 'Intersect Line' > 'Create Profile Graph' functions (3D Analyst Toolbar) to get cross sections of lines from a DEM raster. Does anyone know, if there is a similiar ...
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2answers
38 views

How to set independent path in QgsOverlayAnalyzer >> intersection statement using Python?

How to set independent path in QgsOverlayAnalyzer >> intersection statement using Python? QgsOverlayAnalyzer.intersection(QgsVectorLayer, QgsVectorLayer, QString, bool onlySelectedFeatures=False, ...
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0answers
36 views

How to test polar stereographic projection for a specific longitude intersection?

I'm writing a library that tests grids defined by map projections for intersections, and am running into an issue implementing the test for polar stereographic and rectangular projections - ...