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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 ...
2
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1answer
14 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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7answers
2k views

Intersection algorithm that correctly handles the 180° meridian and poles?

Is there a well known intersection algorithm that correctly handles 180 meridian and poles? For example, let's say we have a list of latitude and longitude values that represent Antarctica. Let's ...
2
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0answers
34 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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1answer
51 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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2answers
218 views

geospatial libraries like postgis

I'm pretty comfortable with postgis, but I realized that for part of my application, having a database is pretty heavy. I'd like to be able to take a stream of Point objects and check against an in ...
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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
297 views

Polygon color on intersect

Using OpenLayers, I am loading a large geojason file of about 4000 polygons. Once the polygons are loaded I want to draw a "LineString" on the map (already done and working). My challenge is that I ...
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0answers
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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0answers
94 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). ...
2
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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 ...
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 ...
5
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1answer
413 views

Rgeos drops associated values when intersecting polygons

I am trying to intersect two SpatialPolygonsDataFrames and get a SpatialPolygonsDataFrame as the result. Unfortunately, using the gIntersection function from rgeos (which works impressively quickly ...
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1answer
250 views

Intersecting polygons in Oracle

Have a polygon in table 2 with its id, no and geometry. In table 1 I have polygons with the same fields. The polygon in table in intersects with a few polygons from table 1.What I am trying to do is ...
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0answers
28 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 ...
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0answers
68 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 ...
3
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1answer
108 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
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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1answer
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 ...
0
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1answer
96 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, ...
5
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1answer
518 views

Apportioning Points at a street intersection (arcgis or mapinfo)

I can't seem to find any evidence of this question, but I'm surprised by that, so pardon if this has been asked. If one is mapping crime location reports, by XY coordinates to streets, to create ...
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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. ...
4
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1answer
253 views

Clip polygon and retain data

I have these two polygons: library(sp); library(rgeos); library(maptools) coords1 <- matrix(c(-1.841960, -1.823464, -1.838623, -1.841960, 55.663696, 55.659178, 55.650841, ...
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3answers
3k views

QGis: Merge intersecting polygons into one which are part of the same feature

I'm not a GIS professional so I hope I use the correct wording, at least I hope you understand my question. Let's say there are 5 polygons in the feature A. In the shape file there are more ...
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0answers
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." ...
2
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1answer
274 views

Creating buffers that will not overlap in QGIS

I am dealing with a .shp with a number of points in it. The distances between points range from ~300m to 5km. I wish to create a 1 km buffer around each point with as little overlap as possible. Each ...
0
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1answer
76 views

How to use Intersect tool in ArcObjects

I'm trying to use the Intersect tool in ArcObjects SDK Java with two feature classes. Here is my code: public void intersectTwoFeatureClasses(Object in1, Object in2, Object out) throws ...
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 ...
3
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0answers
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 ...
2
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2answers
187 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
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 ...
2
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2answers
192 views

Separate a polygon in different polygons depending of the distance to another polygon

I have a reference polygon "R", and others polygons (in grey). I want to separate each grey polygon in multiple polygons, depending on the distance to R with different Buffers : - The red line is R ...
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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0answers
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 ...
2
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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
100 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 ...
4
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2answers
141 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.
3
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0answers
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 ...
2
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2answers
124 views

Sextante modeler feature selection

I am trying to select grids (polygon geometry) that intersect with a building layer. I can do it by using "Select by location" tool and then I generate centroids from the selected grids. There is no ...
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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 ...
3
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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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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 ...
2
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3answers
1k 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 ...
1
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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
81 views

Intersecting Overlapping Polygons Individually in ArcGIS

Map Layers: -Census Tract Shape File w/Population Data -Set of Store Locations with 5 Mile Buffers (Significant Overlap Between Buffers) I have create feature layers for both and I am trying to ...
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1answer
26 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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1answer
254 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). ...
3
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0answers
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: ...