Where features overlap

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PostGIS: Ensure Intersection of 2 Polygons results in a Polygon

I want to ensure that the result of ST_Intersection(polygon1, polygon2) is also a polygon. I initially filtering by ST_Overlaps(polygon1, polygon2) but that seems to only ensure that both features ...
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29 views

Oracle Spatial Returns Different Intersection Results with SRID Defined

I have a set of points and a set of polygons of which I am performing an intersection on to determine which polygon each point lies in. This was performed previously without the projection being ...
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1answer
17 views

Assigning values to a grid cell based on number of intersecting features

I need to create a grid that will include a single value for each cell which represents the total number of "stressors" intersecting that cell. So, the final product will be a 1km grid with cells ...
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37 views

arcpy.Intersect_analysis() returns empty result, but Intersect tool in ArcMap is succesful

I've got two large feature classes that I'm trying to perform an intersect on. Using the following python code, I get an empty output feature class: arcpy.Intersect_analysis(["Schools","Zips"], ...
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22 views

How to check if there is an intersect between two coordinates? [duplicate]

I have two pairs of lat/lon (expressed in decimal degrees) along with their radius (expressed in meters). How can I see if there is an intersect between these two points? How should I deal with the ...
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97 views

convert lat/lon into meters

I have a database of latitude, longitude and radius in the following form: 48180759,11518950,19.0 Both latitude and longitude are expressed in degrees but then multiplied by 1e6 (or 1000000). ...
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1answer
52 views

Finding an ogr2ogr equivalent of SelectLayerByLocation

So I'm trying to take individual grid point buffers and only select the regions that the points intersect with (via SelectByLocation). Generally I run the following code to: Explode multipart ...
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1answer
60 views

Why are a polygon's vertices jumbled after importing KML into MySQL?

This is original KML : <Polygon><outerBoundaryIs><LinearRing><coordinates>104.700355,-3.056064 104.632127,-3.103623 104.608924,-3.103169 104.570166,-3.102411 ...
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29 views

SQL Server : find Intersecting geometries with a geometry using sql query

I asked this question on parallel site (h++p://stackoverflow.com)and think this is a better place to ask such questions I want to find all geometries in a table that intersects with spacial geometry ...
4
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1answer
71 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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70 views

Alternative way to find intersection between two polygon feature classes

I have been working on making a script to find intersection between two polygon ArcGIS feature classes. I can successfully do this in arcpy instances using spatial join or using search cursors on the ...
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1answer
23 views

how do you erase polygons that don't have a line intersection?

I am trying to erase any polygons that do not have a line intersection through them and am unsure of what tool to use using ArcMap 10.1
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31 views

What is a OGRGeometryShadow and why can't I use it in Intersects()-method?

I'm trying to script something with Python and GDAL/OGR and Shapely. What I have: two LineString geometries: "geom1" and "geom2" I made an Intersection: "intersection = geom1.Intersection(geom2)" ...
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1answer
62 views

Computing intersections for each geometry in a table

I have a table with many Linestrings and for each of these Linestrings I need to figure out which other Linestrings, from the same table, intersect with it. If I recall correctly this gives me a ...
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1answer
40 views

Intersect/union two different polygon layers to produce a third polygon type

Can anyone instruct me on the correct way to union/intersect two different layers containing polygons so that a third layer is created containing the attributes of the non-overlapping regions from ...
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2answers
51 views

QGIS failing to complete clip or intersect

I have been trying to perform a intersect (then tried using clip) on a rather large dataset on QGIS. I have been able to complete similar geoprocessing using slightly smaller datasets and the layer. ...
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13 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." ...
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2answers
194 views

Intersect Shapefiles using Shapely

What I'd like to try and do is intersect some point buffers with census tracts, maintain their ID's and the tracts attributes. I found a sample from ...
3
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1answer
126 views

How to create a cluster of crashes?

I have a shapefile with 52K points of road accidents, between 2007 and 2012. Each accident has a severity index. I want show clusters of 5 accidents (at least), for each year, that have a severity ...
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61 views

Most efficient way to intersect overlapping polylines

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 ...
3
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1answer
81 views

Calculating length of road network within a polygon [duplicate]

I have a road network stored in a gdb and some polygons in another gdb. I want to populate an attribute for each polygon with the total length (in km) of the road network that it overlaps. Any idea ...
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26 views

How can I calculate the intersection of a line and the geoid (EGM96)? [closed]

I have a known line (point and vector) described in ECEF (Earth-Centered, Earth-Fixed) coordinates and I need to find where it intersects the geoid (Earth Gravitational Model 1996). Is there existing ...
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1answer
33 views

SQL Server equivelent to Arcmap Intersect for polygons?

I have three different sets of GEOMETRY Polygon datasets in SQL Server that completely overlap. I need to create a new dataset that has a polygon for each unique area of the three layers. So ...
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2answers
103 views

Create Intersecting lines and remove dangles

I have 3 cases shown in the image..In all of them i want to intersect the lines and remove dangles using python in Qgis python console so afterwards i can make a plugin for this work in qgis.In case 1 ...
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2answers
144 views

Split lines at intersection points

I've got some linestrings covering a road network, and need to split them at the crossroads. Does anybody have any idea on how to do it? I'm using QGIS 2.4, with a Postgis 2.1.3.
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65 views

Intersection of a vector linestring and underlying DEM

Following is an screen-shot where ASTER DEM raster layer has been overlaid by a road linestring vector layer. I want to extract those DEM pixels which are lying exactly beneath the linestrings. I want ...
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1answer
37 views

How to find points present in one layer but not in a second layer, using ArcGIS?

I have two layers, A and B, with B consisting of a proper subset of the points in A. How can I produce a third layer, C, consisting of just those points found in A but not in B. In R, I would just ...
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1answer
23 views

arcmap mapping information of 2 layers, how to get rid of non-related results

I have 2 layers on the map: 1 drain line layer and 1 segment layer. The segment layer is covered by the drain line layer. Now I want to get the corresponding attribute values on drainline layer which ...
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1answer
29 views

How to calculate the intersection between WFS layer and a PostGIS table

I need to calculate the intersections betweek a WFS layer and the geometries stored in PostGIS table. Then I should save the geometries of the intersections in a separate PostGIS table. Do you have ...
3
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1answer
111 views

How to calculate the intersected area from a layer with overlapping buffers in qgis

I need to calculate the area of landusetypes in 50m around various dots (all in one shapfile). My problem is, the buffers around the dots are overlapping each over in some places. I tried to ...
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1answer
264 views

How to get Intersection point from two lines (coordinates)

I have tried for ages to find the algorithm for getting the coordinate of two intersecting lines from a given coordinate (latlong). As the picture below suggest. I have two coordinates (A and B). ...
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1answer
27 views

Intersection of triangle and polygon

I have a triangle and an arbitrary polygon lying on the same plane in 3D space. I need to find the fastest way to determine if these two intersect, one is inside the other, or completely separated. At ...
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89 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: ...
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27 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?
2
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1answer
70 views

QGIS Intersection problem

The QGIS Intersection tool is not working for two shapefiles in Version 2.2 or 2.4 (haven't tried earlier versions). I get a new shapefile with all the attributes, but no features. However, when I use ...
2
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0answers
143 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, ...
3
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91 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 ...
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1answer
80 views

PostGIS - Intersects feature to split into linestring

I would like to know if it's possible to intersect feature datasets (multipolygon, polygon, multilinestring and linestring) to get a result as a set of linestrings being split at each intersection ...
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1answer
40 views

Clip polygon features with country boundary ArcGIS Desktop

I am trying to trim the edges of some polygons based on a country boundary. I have tried both clip and intersect, but neither seem to be doing what I want. Below is the image I am working with. When I ...
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33 views

Iterating Intersect Between Dates for single and dual shapefiles of multiple polygons

I'm looking at day range overlap for an animal - to do this I'm looking to generate intersection polygons from the animal's range on day 1 to day 2, then day 2 to day 3 etc., from day 1 to the end of ...
3
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1answer
83 views

Showing Linestring from SQL statement with CartoDB

I have cartodb sql statement to return what polygons are intersected by a linestring, but I'd like to have the linestring visualized over the polygons on the results. Also not add the linestring to ...
2
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29 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 ...
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1answer
47 views

MapInfo incorrectly counting lines intersecting a buffer

I made a buffer for all objects on start and end nodes of polylines then disaggregated them. I then used update table to derive the number of lines intersecting: However this appears to be ...
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1answer
58 views

python code to create an intersection loop with a geodatabase [closed]

I am trying create a loop that will intersect each individual township with a statewide section layer. I am having trouble with the syntax of the intersect tool I think, but maybe it is something ...
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3answers
55 views

Model Builder is not intersecting erased and selected files

I'm having trouble debugging my model that I'm creating in ArcMap 10.1 ModelBuilder. The model is just a simple string of geoprocesses, but there's a point at which the model isn't exporting the ...
2
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1answer
112 views

How to do a “fuzzy” intersection?

I have two layers that look like this: I want the intersection (or whatever the correct term may be) to look like this where the output polygons are the same as the original base layer, just with ...
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1answer
81 views

Closest point on a line segment from point outside the line

From the above pic I found the value x from line (p1,p2) and point a. Using y=mx+b and an imaginary red line which is perpendicular to the black line having slope -1/m and the intersecting point ...
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1answer
141 views

Counting self intersections of linestring using PostGIS?

Is there a way of using PostgreSQL + PostGIS for finding the number of self intersections in a linestring? I have a linestring that goes forward but in circles, and I need to find the number of times ...
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1answer
156 views

Calculate population coverage?

I am relatively new to QGIS and hope I explain this right. I am looking at the percentage of an population that has geographical access to healthcare. Therefore I have one shapefile with village ...
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28 views

Basic Intersect in mysql

I've looked all over but can't find a simple snippet of mysql spatial intersect. Does mysql support it? Does anyone have a working exmaple? Thanks