Where features overlap

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0
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0answers
21 views

Split polygon into four with respect to single point

Some days ago one of my colleague came to ask me a query related to Geometries. The situation is as....There is one Polygon(suppose a city polygon) and there is one point(suppose user's current ...
0
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1answer
83 views

Sextante modeler feature selection

i am trying to select grids (polygon geometry) that intersected with building layer. i can do it by using "select by location" tool. and then i generate centroids from the selected grids. there is no ...
2
votes
1answer
144 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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0answers
22 views

How to intersect more than 2 layers in QGIS

I have a dozen layers, some intersecting with others. Using the Intersect tool only allows 2 layers at a time but can you add extra layers to find where it intersects? Even if it's 3 layers as shown ...
0
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1answer
20 views

Summing the number of intersections with a separate buffer layer

I have dabbled with ArcGIS and QGIS a bit, and I consider myself a self-taught beginner with a whole lot to learn. So, I have two layers: 1) census blocks, and 2) point data. My goal is to calculate ...
2
votes
1answer
93 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 ...
2
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2answers
346 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 ...
3
votes
1answer
65 views

Find intercept WGS84 coordinates between two segments defined by (Lat1-Long1 and Lat2-Long2) and (Lat3-Long3 and Lat4-Long4)

I need to determine the WGS84 coordinates for a point that is defined by the interception of two segments represented by two sets of WGS84 coordinates each (lat1-long1, lat2-long2) and (lat3-long3, ...
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1answer
45 views

Finding closest Intersection between line strings (PostGIS)

I want to find the distance between one point (excavation sites) and a line (rivers) for the cardinal directions. What I thought would be the easiest way is to draw lines between the excavation site ...
-2
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0answers
40 views

intersect zip python

I try to change the python script ExtractData to do the intersection., but until now I fails to do so. i change the funtion : clip_analysis by intersect_analysis. i change also the parameters: ...
0
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0answers
11 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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1answer
28 views

Trying to understand / troubleshoot intersection behavior of postgis

I'm trying to calculate the percent of intersection between two polygons using postgis. I was able to do so successfully for 90% of my polygons, but about 1500 have very unexpected values. I ...
1
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1answer
36 views

Intersection of polygons QGIS 2.2

I have a polygon layer with many circle polygons in it, which are overlapping each other. I now would like to cut of the overlapping areas at their cutting edge: I use QGIS 2.2 and couldn't ...
0
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1answer
75 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 ...
3
votes
2answers
77 views

How to check if vertex exists (on polyline) based on location of point layer using ArcPy?

Using ArcGIS for Desktop Advanced 10.1 (with all extensions) I am building a centerline network that will be used by a MapObjects program to do routing based on "turns at any vertex" (as opposed to ...
-1
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0answers
37 views

How to set input parameters for geoprocessing task that uses Intersect tool?

I have tried to create a geoprocessing task that allows the intersection of two or more layers from my map service. For that I created a model, using ModelBuilder, and I published it as a ...
1
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0answers
16 views

How to set tolerance value of ST_Intersects query in TileMill?

I want to place river names in Tilemill. I use "text-dy" to displace label from the center line of a river. But for labeling polygonal rivers, names extracted from lines are used too. So at a small ...
0
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1answer
24 views

How to detect if a point lies inside a building?

My main motive is to detect if there's in any infrastructure nearby to a given point in a certain radius. For this I am using Places api and using nearbySearch method of it. The problem in this is ...
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0answers
26 views

How to intersect widget using script python arcpy and geoprocessing service? [closed]

Is it possible to develop an intersection widget with geoprocessing service using script python arcpy? I try to do that with ModelBuilder but after publishing, in geoprocessing service i don't find ...
0
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1answer
27 views

How to output parts of layers (shapefiles) that do not intersect using ModelBuilder?

I have two layers (shape files) that I want to select what do not intersect, to after all make a kernel of it. How do I do that in ModelBuilder without scripting? If someone can help me, even ...
2
votes
1answer
368 views

Intersection of drawn polygon with WMS layer features. Better of two methods?

Scenario: Several WMS layers with polygon features. Objective: Draw a polygon with OpenLayers and allow it only if doesn't not cut any features in WMS layer. It can contain the features as a whole ...
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0answers
24 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 ...
2
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1answer
46 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 ...
5
votes
1answer
425 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 ...
0
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1answer
209 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 ...
3
votes
3answers
450 views

How to find if two polygons Intersect in python?

I'm looking for an algorithm, high level solution, or even a library which can help me determine if two polygons intersect, in Python. I have the vertices of the two polygons (These are single part ...
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3answers
60 views

Geometry vs geography for line-to-polygon intersection

I have two WGS84 NAD83 shapefiles, one polygonal, the other containing lines: Geometry: Polygon Feature Count: 1294 Extent: (-79.761059, 44.991143) - (-57.105486, 62.582865) Layer SRS WKT: ...
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0answers
45 views

How to count points once with overlappying polygons?

All, We're using parcel data (polygon) to count student locations (point) based on parcel type. We're doing this using SQL and the ST_Intersects function. It works great, except the City and County ...
4
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2answers
126 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 ...
0
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0answers
15 views

GRASS GIS - v.select- ERROR: bad allocation -

I'm quite new to Grass GIS. I have two vector maps, one of a grid (each grid cell is a polygon) and one of a much larger polygon. I've been trying to select the grid cells that lie completely within ...
13
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6answers
5k views

How to use ST_Intersection?

Here's a quick summary about what I'm trying to do: I have 3 tables in Postgres, 'a' and 'b', each have a Polygon column, and 'c' has a Point column. What I'm trying to do here is to get the ...
1
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2answers
44 views

Is there an average size for British postcodes?

Is there an average size for British postcodes? Or a method of determining the size for a particular British postcode? Thanks. Considering creating a related program and this would be valuable ...
0
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0answers
28 views

Quickest method for determining which postcode is 2 miles north of original postcode? [duplicate]

What is the Quickest method for determining which postcode is 2 miles north of original postcode? For instant L17. I know how to determine the distance between 2 points as below, but the above ...
0
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1answer
39 views

Hard to get my head around, generating average price for houses in each quadrant

I'm able to determine the average price of houses sold in a particular area (like the squares on image below) dependent upon postcode. Although I can generate the average sale price for a particular ...
0
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1answer
13 views

How to select the identities of a layer present just in one identity of another layer

I'm a student approaching to QGIS 2.0.1-Dufour. My goal is to know how much identities of a layer are present just in one identity of another layer. I tried both with the tools "spatial query" and ...
5
votes
1answer
171 views

Performance in calculating raster statistics in PostGIS

I'm trying to calculate raster statistics (min, max, mean) for each polygon in a vector layer using PostgreSQL/PostGIS. This GIS.SE answer describes how to do this, by calculating the intersection ...
1
vote
2answers
30 views

How can I populate a field of the polylines to indicate if they intersect?

I have two feature classes, one ploylines, one a buffer. How can I populate a field of the polylines to indicate if they intersect?
1
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0answers
39 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 ...
3
votes
1answer
58 views

Verifying the number of times a line crosses other lines

I have a series of lines that represent streams. I have a stream line and two flowpath lines in one feature class and two banklines in another feature class. Total of five lines. I then have a feature ...
0
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1answer
52 views

Cut polylines at intersections in QGIS (or how many km road for each country)

I want to measure how many km a road stand on each country it intersect (i.e. how many km of the european road "E45" stand on Italy, Austria, Germany, and so on). I have a polyline-shapefile with the ...
1
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1answer
41 views

How do I convert OS coordinates (X and Y) to longitude and latitude coordinates?

How do I convert OS coordinates (X and Y) - Eastings and Northings to longitude and latitude coordinates? For example X and Y below X (Eastings): 347904 Y (Northings): 287484
1
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1answer
52 views

How do I figure out the grid references (Eastings and Northings) necessary to create a circular 1 mile radius around one location?

How do I figure out the grid references necessary to create a circular 1 mile radius around one location? For instance: Grid Reference: SO 47904 87484 X (Eastings): 347904 Y (Northings): 287484 ...
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0answers
45 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 ...
0
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0answers
25 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 ...
3
votes
1answer
92 views

How do I figure out the longitude and latitude coordinates necessary to create a circular 1 mile radius around one location?

How do I figure out the longitude and latitude coordinates necessary to create a circular 1 mile radius around one location? I don't mind how many coordinates that takes. For instance: Latitude = ...
0
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0answers
21 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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0answers
21 views

Method of extracting the intersecting areas of multiple overlapping polygons (5) and classifying intersects based on spatially joined points

I have concave hulls surrounding clusters of data points which has led me to a lot of overlap and fuzzy boundaries. I am attempting to intersect the overlapping areas but have a minimum of 5 different ...
1
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0answers
43 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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2answers
624 views

How to delete overlapping polygon features from one of two layers?

I really need your help! I have two overlapping layers of polygons, and i need to somehow erase the areas the overlaps. -This way i should end up with two layers of non overlapping polygons. Sounds ...
1
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0answers
49 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 ...