Where features overlap

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7
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0answers
338 views

Performing buffering and intersection with script in PyQGIS

I wrote a script that performs the intersection of two layers: The first Layer -> layer1, represents the rivers The second Layer -> layer2, represents a set of circular dots distributed in a ...
4
votes
0answers
48 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, ...
3
votes
0answers
50 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 ...
3
votes
0answers
129 views

How to compute (X,Y,Z) of a point from given attributes

Is there a way to compute the geodetic coordinates (Earth Centered) of a satellite S(x,y,z). The original problem is to compute the footprint of an antenna, given the following information: ...
2
votes
0answers
23 views

PyQGIS: intersection of one node layer with two polygon layers

I´m new with the use of PyQGIS and I´m working in a problem applied to a water supply systems modelling, where I need to distribute the water demand in about 5000 nodes (network junctions). I´m ...
2
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0answers
44 views

QGIS Atlas zoom to intersection between two different layers

I have two polygon layers, one is about different land owners boundaries and is used for atlas generation, and the other is about forests inside each property. In atlas generation sometimes i want to ...
2
votes
0answers
91 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 ...
2
votes
0answers
71 views

Multiple layer intersection

I am trying to find a way with qgis/python to get the intersection area of more than 2 layers. All the tools in Qgis take just the 2 input layers. ='( For example in the image below, I have 4 ...
2
votes
0answers
368 views

Create circles around a point on a map measuring the radius in hours

Disclaimer: I am not experienced in GIS and hope this question fits in this category. I was wondering whether it is somehow possible to create a circle* around a city, using Google Maps or the like, ...
2
votes
0answers
52 views

Distribute Hotel Beds According to Population Density in Buffers using ArcGIS for Desktop?

I am running an ArcGIS for Desktop analysis where I am plotting competing hotel facilities and then distributing their beds in a 5-mile buffer around the site. I would like to distribute the beds ...
2
votes
0answers
297 views

PostGIS: How to distinguish overlapping routes (i.e., LineStrings) based on their direction?

I have a set of routes which are represented by LineStrings in my PostGIS database. These routes represent journeys that people make. I want to come up with routes that (a) overlap, and (b) have the ...
2
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0answers
164 views

How to Simulate Venn Diagram of Buffers using QGIS?

For the sake of simplicity, suppose I have only 2 points on one layer. Point A have population of 100, and point B have population of 150. I do find buffer of these 2 points and it is intersect. I ...
2
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0answers
363 views

How to best intersect vector data with raster data?

I have Open Street Map [OSM] data imported so that I can access the geometry of buildings. I have also loaded SRTM digital height data from NASA from a GeoTIFF raster. I have projected the raster into ...
2
votes
0answers
240 views

How to copy the contents of an attribute from one vector layer to another one that touches it or intersects it?

I have 2 layers that intersect, called layer A and layer B. Layer A has an attribute (X) that I want to copy wholesale (for the whole layer) to layer B, so that when object A1 intersects object B1, ...
2
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0answers
434 views

3D features (Polyline, Polygon) intersection library

For my research I am looking for a (python) library to get the intersection of some 3D features. The features can be Polygons or Polylines. Mostly I need to intersect a plane with my features and get ...
2
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0answers
216 views

How could I make this PostGIS query run faster?

SELECT st_band(rast, 1), st_width(rast), st_height(rast), st_bandpixeltype(rast, 1), st_bandnodatavalue(rast, 1), st_scalex(rast), st_scaley(rast), st_upperleftx(rast), st_upperlefty(rast) FROM ...
2
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0answers
653 views

cant find point/polygon intersect using qgis (windows only)

below i describe the method i am using. i have 2 machines: 1 ubuntu linux, qgis 1.4 - intersection works 2 WIN xp, qgis 1.8 - intersection dows not work hopefully, someone will ...
1
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0answers
22 views

Joining polygons to points when the points fall in the intersection of polygons. QGIS

I am using QGIS. I am hoping to join a set of geocoded points to polygons in such a way that the new snapefile will be points that have a new field which lists the attributes of the polygon it lies in ...
1
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0answers
51 views

Select Layer By Location (Management) gives different result in ArcPy and ArcMap?

I have two line Shape files. When I use the Select layer by location tool to select two intersecting lines, it works fine and selects only lines which are actually intersecting. But when I use this ...
1
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0answers
22 views

How do I find whether a line is intersecting a circles with small radius on earth?

Algorithm mentioned in how-to-pick-up-line-segments-which-is-inside-or-intersect-a-circle seems to be working fine for circle with radius > 50 miles. But when coming to circles with radius < 50 ...
1
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0answers
29 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), ...
1
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0answers
39 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 ...
1
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0answers
93 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 ...
1
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0answers
23 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. ...
1
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0answers
31 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 ...
1
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0answers
54 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 ...
1
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0answers
99 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 - ...
1
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0answers
33 views

pgr_nodeNetwork doesn't place new nodes properly

I wanted to use pgr_nodeNetwork tool to split lines where there's no vertex on intersection. The tool doesn't seem to work as expected, though. It doesn't place new nodes right where the two lines ...
1
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0answers
66 views

Tabulate Area 2 Tool not returning correct area

I am having trouble with the output of the "Tabulate Area 2" tool in the following update: http://blogs.esri.com/esri/arcgis/2013/11/26/new-spatial-analyst-supplemental-tools-v1-3/ I have a layer of ...
1
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0answers
137 views

QGIS Intersect returns empty layer

I'm following these instructions from the FCC: https://transition.fcc.gov/form477/Geo/finding_census_blocks_in_qgis.pdf Everything works just fine up until step #6, where the Intersect tool is used. ...
1
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0answers
60 views

ogr2ogr: export intersected gml using shapefile

I'm trying to do the same as the ogr2ogr example given by http://gis.stackexchange.com/a/119404/6458 The difference is that my inputs are a GML and a shapefile. Export.shp should only contain the ...
1
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0answers
63 views

Problem running intersect vector processing with line shp file and polygon shape file

I have been trying to run intersect on two shp files, one is line, the other is polygon. Although processing appears to take place and a new shp file is created and added, nothing is visible. I have ...
1
vote
0answers
129 views

PostGIS: intersection of a polygon with 2 rasters

I'm trying to get the intersection of a Polygon with 2 raster layers in PostGIS. The rasters have the same size and pixel size and I'd like to retrieve for the polygon a list of something like that: ...
1
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0answers
467 views

Leaflet - Check if polyline intersects polygon

What is the best way to determine if a polyline (not just the vertices) intersect a polygon? Or checking if the polygon contains any of the polyline? I am checking within a function where my polyline ...
1
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0answers
115 views

QGIS 2.8.2 - Using spatial expressions in labelling

I'm creating some hard copy map output from QGIS. I want to use an expression to suppress labels for some features on a layer when another feature from another layer intersects with those features. ...
1
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0answers
58 views

Polygons in Polygons

I have 2 layers, they represent 2 different data. I did a spatial join to see the polygons that fall in the other layer using the match option as identical. Before, i used the intersect as the match ...
1
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0answers
322 views

Efficient way of determining polygon intersection with bounding box

I have a set of polygons, and I need to check whether they are intersecting with a given bounding box(rectangle). What I am doing is, I am taking every vertex of polygon and checking whether it's ...
1
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0answers
72 views

Incomplete results from an intersection

I am trying to map the density of buildings in flood-prone areas. In order to do that, I created a grid of equal-sized squares. I want to intersect the layer of buildings with the grid so I can ...
1
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0answers
50 views

Select features intersecting a linestring in QGIS

I wrote a python plugin that grabs all (vector, linestring) features between two points on the map. At the moment, I select all features intersecting the rectangle around these two points, and then ...
1
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0answers
13 views

Finding polygon from two arcs using CLI tools or some library

I'm trying to convert from textual representation into a set of arcs and lines. The 'input' I have is: The area is within lines joining two semicircles with a radius of 0.67 NM centred on: 641139N ...
1
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0answers
100 views

How to count unique lines intersecting with polygons?

Like u can see on the attached picture i did an intersection with a Raster (purple squares) and the red lines. What i need to know is the count of joins each line has for each square. What makes ...
1
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0answers
189 views

Determine lat/lon intersection on earth from point in space along 3d line

I have a known point in space with a lat,lon,alt. It has a camera with a line of sight and a angle of field of view. I can take the central point and calculate each corner vector of the field of view, ...
1
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0answers
61 views

How to cut parallelogram with intersecting line?

I have a very specific set of circumstances under which I need to break a parallelogram into 2 pieces. The parallelogram obviously always have 4 vertices and the intersecting line intersects the ...
1
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0answers
50 views

Run intersects function in PHP?

I have an old script that used to connect to a postGIS DB and basically perform: $sql="select * from mobile.regions_ne where intersects(geom_wgs84,GeomFromEWKT('SRID=4326;POINT (".$lng." ".$lat." ...
1
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0answers
29 views

Data Transfer of a point on line using the anchor point

Can I a line feature, the anchor point touches a point feature transferred the field value, even when the point touches another line(s)? How does this work?
1
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0answers
36 views

Can a joined-layer have its attribute changed depending on what layers are selected/deselected?

Using QGIS, I have a polygon-grid layer which covers everything, Layer_All joined with 2 other grid layers: Layer_1 and Layer_2, both of which intersect at various points. I would like Layer_All to ...
1
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0answers
282 views

How to simplify a self intersected / self overlapped polyline using ArcObjects?

I have a self intersected polyline, how can I break it into 5 records stored in the same table using arcobjects? (splited by vertices and the intersection point) Here is what I have got and it ...
1
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0answers
350 views

Intersection between a ray from lat, lon, alt, with pan, tilt and earth's surface

I have a problem that consists of finding the intersection point between a ray from a given lat, lon, alt, that is looking to a given pan and tilt angles and the earth's surface. I need the lat, lon ...
1
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0answers
120 views

How to get intersected points between polygon and line in desired order

I have polygon for example "POLYGON((5 1, 6 1, 6 5, 5 5, 5 1))" that I want to intersect with line "LINESTRING(0 2, 10 2, 10 3, 0 3, 0 4, 10 4)" and get intersection points in the order that they ...
1
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0answers
94 views

Trouble intersecting a polyline and contours (Hack index / stream length gradient index)

Working on creating polylines for measurement using SL index (hack index). So far I have the main trunk of a stream, and contours at 10m. What I am trying to do is a) get the elevation at each ...