Where features overlap

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0
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1answer
405 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 ...
2
votes
0answers
26 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 ...
0
votes
2answers
44 views

How to select the features touching other feature? [closed]

I have two shape files. Buffer of a river line Parcels nearer the river I need to find out the area of the parcels only touching the river line. I used the intersect tool and it gave me only the ...
5
votes
1answer
580 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 ...
1
vote
1answer
33 views

Find intersections between spatial lines and points using R

This question assumes that I'm using R with the sp and rgdal packages installed. Now that I have a set of spatial segments of class SpatialLinesDataFrame (called 'segmentData') and a set of spatial ...
4
votes
1answer
49 views

How to find the distance from a point to a polygon, via another point, in R

I am trying to calculate the distances between a central point, and the edge of a polygon, along straight lines drawn between the central point and another set of points (where necessary extended ...
0
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0answers
5 views

Intersection of 2 feature class in flex

I have two feature class and the requirement is to intersect both of them in flex. I'm querying on one feature class, getting its geometries. I tried doing union of all the geometries of the layer ...
1
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0answers
19 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 ...
0
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0answers
19 views

Allocation of data by Voronois to admin units according to area in QGIS? [duplicate]

In QGIS, I need to assign values from Voronoi cells into admin 2 units (e.g., counties) with a weighted average according to the amount of territory of each county covered by the cell. So, for ...
1
vote
2answers
251 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 ...
1
vote
0answers
46 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
21 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
1answer
79 views

How to select polygon features that intersect a line feature using pyqgis?

Is there an easy way to select all features in a polygon layer that intersect (overlap) a line feature? I need to implement this in python using QGIS, thus pyqgis. This code illustrates what I am ...
0
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0answers
65 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
vote
0answers
45 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 ...
2
votes
1answer
75 views

How to extend line features up to their intersection point in QGIS?

Is there a tool or plugin in QGIS to extend line features up to their intersection point?
14
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3answers
3k views

Identifying road intersections using PostGIS

I'm trying to identify where roads intersect each other, and to make a point at this intersection, with the number of roads that form the intersection listed. I was wondering if there was some way ...
0
votes
1answer
424 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 ...
2
votes
1answer
126 views

Extracting intersection areas in R

I have two polygons. One contains fields(X,Y,Z) and the other contains soil types (A,B,C,D). I want to know what area of every field contains which type of soil. I tried the following: ...
0
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0answers
17 views

polygonize some raster pixels based on their value in PostGIS

I need to extract and polygonize only those pixels of a raster that have a value (e.g.) greather than 2000.0 The reason is that I wish to do an operation like the following one (which is done only on ...
3
votes
1answer
186 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 ...
0
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0answers
35 views

Calculating where the Z values of two rasters intersect

I have several raster layers which are depth horizons, one of these horizons cross cuts the others and I would like to calculate the line along which this occurs. i.e. the line along which the Z value ...
0
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0answers
45 views

A faster polygon intersection tool than rgeos gIntersection in R?

I'm looking for a R function able to retrieve the polygon intersecting between two SpatialPolygonsDataFrame. I need to use R and the rgeos::gIntersection() is too slow in comparison with ArcGis...
18
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5answers
4k views

PostGIS: Select features that do NOT intersect

This seems to me like such a simple question (and it probably is) yet I cannot seem to find an example that gives me the answer. Using PostGIS, I just want to select points that fall outside of ...
1
vote
1answer
45 views

Ratio policy for Intersect in ArcGIS Online?

I have two polygon layers in ArcGIS Online (for organizations) stored as Feature Layers; one is population block, another is the AOI polygon. They are overlapping and I want to find out what portion ...
1
vote
1answer
69 views

ST_Intersection for polygons

I'm looking for a query that returns overlapping areas of two tables with polygon geometries. Using row_number() over() the entries of the gid column are not unique in the case of dumped ...
6
votes
1answer
103 views

What is the difference between Spatial predicates “Covers” and “Contains”?

I try to understand the Spatial predicates of the DE-9IM Intersection matrix. I don't get the difference between predicates Covers (respective CoveredBy) and Contains (resp. Within). I try to draw ...
2
votes
2answers
62 views

How to map a building to only one grid which contain more than half of its area using qgis?

I have a shapefile of a city map and I have created vector grid as polygons. After intersecting the two shapefiles, a building will map to all the grids it overlaps. However, if I just want it to ...
2
votes
1answer
21 views

Labelling polygons intersecting another polygon file

I have a series of polygons representing land packages and another shape file representing contour polygons of flood elevations in steps i.e 2-5m 5-10m >10m. I am wanting to label a polygon with the ...
2
votes
2answers
164 views

Showing OpenStreetMap intersections in ArcMap?

I'm trying to carry out a few tests on OpenStreetMap data to test its quality, using ArcGIS. One of the things I'd like to investigate involves checking that all road intersections are represented ...
0
votes
1answer
67 views

ST_Intersect with ogr2ogr and Spatialite

I am trying to intersect Spatialite datasets with ogr2ogr, the OGR Virtual Format and SQL Syntax. I can't seem to locate whether the error is in my SQL query or my VRT file. Data ...
1
vote
4answers
1k 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 ...
0
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0answers
127 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
vote
2answers
118 views

Adding Nodes to Linestrings at Overlapping Points with Polygon Layer in Spatialite

I have two Spatialite tables. A table called 'lines' which contains a PK column called OGC_FID and a LINESTRING column called GEOM. A table called polys which contains a PK column called OGC_FID and ...
7
votes
3answers
3k views

Extract Overlapping Polygon Data to Points

I have a polygon data set of corn yield collected by a combine. However, as the combine drove through the field, there was slight overlap between passes, leading to overlapping polygons within the ...
0
votes
0answers
39 views

Intersection of two lines from points with direction angles [duplicate]

Given two points and direction angles from each point to a third point, but no distances, how do we get the x,y coordinates of the third point? In other words, how to find the intersection point where ...
0
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0answers
35 views

Determining intersection between list of points and list of linestrings?

I'm coding in php. I have a list of point coordinates (very large one) and a list of linestring geometries (large too). I'd like to determine for each linestring, the point coordinates that ...
0
votes
1answer
55 views

Nearest intersections outside the polygon in ArcGIS for Desktop?

I have two layers, a street network and a polygon, and I want to find the nearest street intersection points just outside the boundary of the polygon. For example some area is closed by police and I ...
1
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0answers
38 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 ...
0
votes
2answers
79 views

Points within polygon in QGIS [duplicate]

I have a shapefile with polygons. And I have a csv file with points. Now I want to know for each point in which polygon it is situated. Every polygon has a number, so I want to create a file where you ...
1
vote
1answer
77 views

Calculate area intersected areas, problem [closed]

(I'm working in QuantamGIS) I intersected two layers creating a new layer. Within the attibute table of this new intersect layer i would like to calculate the new areas. However, it just doesn't ...
2
votes
2answers
4k 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 ...
4
votes
3answers
70 views

How to find intersections of lines less than 45° in FME

I'm trying to identify intersections of electrical transmission lines that are less than 45° in FME. While, in theory, this doesn't seem like such a daunting task, in practice, it's proving quite ...
1
vote
1answer
116 views

QGIS 2.6 simplify a road network to obtain the intersections

In QGIS 2.6.1 in Ubuntu, I want to measure the density of block in this city (FYI my final aim is to measure the TOD level). I have the road network from French national IGN dataset BDTopo. I have ...
0
votes
1answer
168 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 ...
1
vote
0answers
28 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 ...
-3
votes
2answers
61 views

Fractional Area Calculation

I have a file (in both raster and vector) of different districts in a country. I have also made a grid of 1 deg * 1 deg (both vector and raster) of the country. I want to calculate the area of each ...
4
votes
2answers
452 views

Keep nonintersecting polygons during clip

I am using ArcMap 10. I have two datasets, one of which consists of many small contiguous polygons, and one which has many small non-contiguous polygons. The first dataset is census blocks, and the ...
6
votes
1answer
5k views

can I extract overlap of polygons within the same layer?

I am trying to extract the overlap of polygons that are within the same layer in 10. The layer came from a buffered street centerline and I'm trying to extract and delete the intersections from the ...
5
votes
2answers
6k views

How to repair topology of a shapefile?

I performed an object-based image analysis using ENVI EX, and each of the classified features were exported as a shapefile. I transferred those shapefiles into ArcMap 10, and tried to intersect them ...