Where features overlap

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2
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2answers
195 views

How to fix overlapping polygons using ArcGIS for Desktop?

I'm using ArcMap 10.3. I have a layer of different land use types. After calculating the percentage of each land use in the catchment using tabulate intersection, I found out that the percentage of ...
0
votes
0answers
90 views

Calculating intersection between lines with GeoTools (java)

I have ArratList<Segment> (N segments - array size is N) when: public class Segment { Node vertex_1; Node vertex_2; } public class Node { double latitude; double longitude; } ...
0
votes
0answers
24 views

Finding and labeling intersections between polygons on a shapefile

I have two shapefiles-- one is labeled islands, the other is unlabeled parcels of land on some of the islands. My issue is that I need to label the islands that have parcels of land. My instinct is to ...
1
vote
1answer
33 views

Using PostGIS Intersection to carry fields from input layers into output layer

I'm having trouble carrying over the attributes from the input layers in my PostGIS intersection below: CREATE TABLE intersection_output AS (SELECT ST_Intersection(a.the_geom, b.the_geom) FROM ...
1
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0answers
66 views

QGIS Intersect returns empty layer

I'm following these instructions from the FCC: https://transition.fcc.gov/form477/Geo/finding_census_blocks_in_qgis.pdf Everything works just fine up until step #6, where the Intersect tool is used. ...
0
votes
1answer
57 views

Creating an intersecting linestring layer from two polygon layers using some tolerance

I have two postgis layers: The first layer contains the sidewalks of my town (polygons in blue). The second one contains the pavements (roads) of my town (polygons in brown). The map looks like ...
1
vote
2answers
41 views

Getting year from a field of type character varying

I did an intersection between two tables and the resulting field has an sdate of type character varying (29). An example value is 2012-01-13 05:00:00. How do I get just the year from it? I want to ...
7
votes
1answer
147 views

Visualizing road Intersections & connections in ArcGIS

I am working with polylines (roads) in ArcGIS and I was wondering if there is a possibility to somehow show intersections as well as connecting parts of all the different road-segments. Also, would ...
3
votes
2answers
109 views

Intersect two polygons with same FID

I need to perform an intersection between two layers, one is blocks and the other is buffers for each block which are of the same size of the road. Blocks and buffers share the same FID. What I'm ...
0
votes
1answer
462 views

SQL Server Spatial Querying

I am looking for ways to learn querying for SQL Server Spatial (2008/2012). I have a table created from Shape2SQL and have been trying to run a simple intersection query to get results from that ...
4
votes
1answer
74 views

Slow Planning for Postgis ST_Intersects

I am trying to run the following query: SELECT * FROM fences where ST_Intersects(geom, ST_GeomFromText('POINT(-73.990452 40.994184)', 4326)) When I run Explain Analyze I get the following: "Index ...
0
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0answers
27 views

Intersecting polygons to a focal polygon with the same cell ID and also obtaining the length of the joining edge

I have a series of polygons, where there is a focal polygon (a type of coral reef). The other polygons are cut to the centroid of a cell where the focal polygon is included. The cell ID is given by ...
0
votes
0answers
18 views

how to use st_intersection() with re-projection in POSTGIS?

This is a shipping route from 'portland to busan' and I want to check the route against land_polygons like how much distance is traveled by a route through land.And the problem is while checking the ...
0
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0answers
26 views

QGIS and Ghydraulics: add attribute fields from intersecting points to line layer

I have lines (pipes) and points (junctions). There is one point at each connection between two lines, so that every line has a start and an end point. Now I want to fill the attributes "start point" ...
0
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0answers
64 views

How to choose a projection for area measurement on building to continental scales?

I have many geographical objects described as polylines, polygons, multipolygons. All objects are in WGS84. Object could be: a building, stadium, park, street, highway, city, state, even country and ...
2
votes
1answer
130 views

Difference between intersect {raster} and gIntersection {rgeos} in polygons - R?

I am interested in knowing the difference between tools: intersect {raster} and gIntersection {rgeos}** tools in R. I have several overlapping polygons and I am interested in their overlap, but mostly ...
3
votes
2answers
144 views

What percentage of polygon x is in raster pixel y, efficiently

I feel this is a competition worthy problem, due to its size. I would like to weight a set of raster pixels to the attributes of a set of polygons. To do this I need to know the proportion of each ...
2
votes
2answers
157 views

Avoid intersection is missing QGIS 2.10, 2.8.2

I need to digitize a lot of polygons and I want to ease my work with the 'avoid intersection' button so that the new polygons do not overlap. In the manual I found (for version 2.6) that the button is ...
1
vote
1answer
224 views

How to SELECT all points within a GeoJSON polygon in PostGIS

I have a GeoJSON polygon, and a table with lots of points. I want to SELECT all points that are within an arbitrary GeoJSON polygon. How can I do that with PostGIS SQL?
4
votes
1answer
206 views

Find Intersection of Two Circle given Lat/Lon and radius

I am attempting to calculate the intersection of two circle on the Earth with a given latitude, longitude and radius. I started with this post. These circle will never be more than 100 km in diameter ...
2
votes
0answers
52 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 ...
2
votes
1answer
202 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 ...
0
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0answers
14 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 ...
4
votes
1answer
68 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 ...
1
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0answers
47 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
votes
0answers
20 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
0answers
49 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
0answers
103 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
vote
1answer
332 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
310 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
52 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
2answers
315 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?
0
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0answers
26 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 ...
0
votes
0answers
53 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 ...
1
vote
0answers
141 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...
1
vote
1answer
127 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
123 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 ...
7
votes
1answer
205 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
96 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
25 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 ...
0
votes
1answer
202 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
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0answers
275 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 ...
0
votes
0answers
40 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
votes
0answers
38 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
67 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
vote
0answers
54 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
213 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
111 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 ...
4
votes
3answers
134 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
0answers
47 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 ...