Where features overlap

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2
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1answer
165 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 104.5588,-3....
0
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0answers
2k 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 ...
7
votes
1answer
219 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 ...
0
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0answers
406 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 ...
0
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1answer
54 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
1
vote
1answer
277 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)" ...
1
vote
1answer
105 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 ...
1
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1answer
1k 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 ...
2
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2answers
181 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. ...
1
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0answers
53 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." 0)')...
4
votes
2answers
4k 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 http://www.macwright.org/2012/10/31/gis-with-...
4
votes
1answer
178 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 ...
4
votes
1answer
213 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 ...
3
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0answers
127 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 ...
2
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0answers
52 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 ...
2
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1answer
91 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 ...
2
votes
2answers
449 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 ...
6
votes
2answers
1k 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.
5
votes
1answer
135 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 ...
1
vote
1answer
43 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 ...
1
vote
1answer
36 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 ...
1
vote
1answer
53 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
votes
2answers
110 views

Analysis of lines in a point in QGIS

I have 33 layers, 1 with points and 32 with lines. I want to extract/highlight the points where more than one line is intersecting. I have tried with buffers but I'm not getting anywhere.
3
votes
1answer
262 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 intersect/...
1
vote
4answers
3k views

How to get intersection point from two lines (two coordinated points and two bearings)

I have tried for ages to find the algorithm for getting the coordinate of two intersecting lines from two given coordinated (latitude and longitude) points. As the picture below suggests, I have two ...
1
vote
1answer
108 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 ...
3
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0answers
139 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: Antenna(x,...
1
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0answers
30 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
votes
1answer
364 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
votes
0answers
379 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, ...
6
votes
0answers
384 views

Performing buffering and intersection with script in PyQGIS [closed]

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 ...
1
vote
1answer
351 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 ...
0
votes
1answer
249 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 ...
4
votes
1answer
314 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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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 ...
1
vote
1answer
123 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 ...
0
votes
1answer
298 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 else....
1
vote
3answers
93 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
votes
1answer
253 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 ...
1
vote
1answer
287 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 x, ...
5
votes
2answers
424 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 ...
3
votes
1answer
408 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 ...
1
vote
1answer
1k views

Iterating over all features in featureclass to intersect them individually with polygon using ArcPy?

I've got a point featureclass, and I'm trying to individually intersect each feature with a polygon featureclass to get some information about which polygon each feature is in. I did one intersect ...
2
votes
1answer
179 views

Calculating countries flown over on flight path

Say I have two airports given. I can then get their coordinates. Now that I have the beginning and end coordinates I can draw flight-path from the two locations. Now my question is that given two ...
0
votes
1answer
95 views

How do i rescale feature classes of different scales for intersect analysis?

before I intersect 2 feature classes of different scales (e.g. 1:200,000 soil map and 1:25,000 land use map), should I rescale them like how u would resample raster datasets to the same resolution ...
0
votes
1answer
222 views

Intersecting great circle arcs and polygons

I am trying to find the point of intersection between a great cirle arc and a polygon. I am working in long/lat, where I am given the endpoints of the great circle arc, A and B, and the vertices, C, ...
0
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1answer
63 views

Get attributes from intersecting lines to label generated intersection point

I have an urban road network (as a feature class), consisting of only polylines. I have to make a database of all the intersections between the streets. The problem is that as I generate those ...
2
votes
2answers
412 views

Is it best to use multipolygon or polygon features for large intersect operations?

I have two large layers that I want to do intersect operations. One is municipalities and the other is landuse. Right now, the landuse layer is of MultiPolygon type that is, for the entire state, I ...
0
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1answer
174 views

postgis finding lines that touch and update

I am not much of a postgis guy so please bear with me. I have a subset of lines representing exits and roads around those exists. Main roads and exists can be distinguished by their class attribute (...
0
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0answers
121 views

How to overlay polygons that are in the same layer

I need to INTERSECT many polygons that are in the same layer. Actually each polygons from my layer represent an area of influence from one specific bird species. Since I used to use ArcMap, I found ...