Where features overlap

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5
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2answers
472 views

How to extract value from a raster based on lat and lon?

I have several netcdf files that I can read using the netCDF4 library in python. The data is gridded in 4320 rows and 2160 columns. I also have a list of lat/lon (in decimal degrees) and I am trying ...
4
votes
1answer
92 views

PostGIS > Intersect two circles. Each Circle must be built from Long/Lat degrees plus radius

I'm trying to figure this out, so I wanted to try asking to the experts. This question is related to PostGIS (from postgresql). What I want is: 1) Based on a longitude and latitude I want project ...
0
votes
2answers
263 views

Python buffer points and clip with line-segment (OS Open Roads in BNG) [duplicate]

I have an array of points (in latitude, longitude coordinates) which I would like to buffer and dissolve (into a polygon) and then intersect the Ordnance Survey Open Roads (projected in BNG) with that ...
0
votes
0answers
42 views

Use ArcMap to determine Polyline overlap, at a certain tolerance, against multiple other Polylines

My goal: Take one fiber route and see how much of the route is within a given distance from 0 other routes, a single route, two routes, and three or more routes. I have used the intersect function to ...
7
votes
2answers
80 views

Tool that modifies number of vertices but not the feature itself

Do you know the reason, why some ArcGIS tools (like Clip and Intersect) modifies number of vertices, even if the feature is not modified itself? Like on the picture, I use Clip and Intersect on line ...
2
votes
0answers
58 views

Intersect does not fully process [closed]

Goal: Use python script to find overlap between various shapefiles in folders Inputs: folder 1 with multiple shapefiles and folder two with multiple shapefiles Method: #First intersection ...
2
votes
3answers
173 views

Efficiency in PostGIS: objects near point- ST_Intersects around buffer Vs ST_DWithin

I need to find all buildings in radius of 25m from given location. I thought about 2 PostGis quires that can handle this, when I run it they both give same time execution. But I want to know which one ...
1
vote
1answer
76 views

Create common vertex where line was snapped to another using “snap to segment”

I have a schematic diagram within QGIS consisting of a single layer of line segments. Lines have been snapped to others using "snap to segment". When using the snap to segment option the two lines ...
2
votes
2answers
298 views

QGIS 2.10.1 Clipping Algorithm Results In Empty Layer

I apologize for the redundancy of this issue, but I have explored all the information I could find over the past couple days and have yet to find a solution to what seems to be a very simple task. I ...
2
votes
1answer
38 views

QGIS: How to scale attributes when clipping / intersecting

I'm working on a project involving a ratio of frequent travellers / population divided in Forward Sortation Areas from Canada Post (FSAs are the first three characters of a postal code: A1A). I ...
0
votes
0answers
28 views

Enclosing building models from bottom (Missing GroundFeatures) using FME?

I have 3D building model of the city and I would like to export it to proper CityGML model. I am trying to find out, how to make an intersection of building and terrain in order to make "...
1
vote
0answers
74 views

Tabulate Area 2 Tool not returning correct area

I am having trouble with the output of the "Tabulate Area 2" tool in the following update: http://blogs.esri.com/esri/arcgis/2013/11/26/new-spatial-analyst-supplemental-tools-v1-3/ I have a layer of ...
2
votes
2answers
571 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
1answer
196 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
31 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
37 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
vote
0answers
167 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
81 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
69 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
206 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
136 views

Intersecting 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 ...
1
vote
1answer
1k 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
122 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
votes
0answers
27 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
votes
0answers
41 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
82 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
252 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
255 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
315 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
373 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
379 views

Finding 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 How to calculate the intersection of 2 Circles? These circles ...
2
votes
0answers
78 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 layers ...
2
votes
1answer
496 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
98 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
vote
0answers
65 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 ...
1
vote
0answers
67 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
142 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
890 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 ...
1
vote
0answers
544 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
123 views

QGIS 2.8.2 - Using spatial expressions in labelling

I'm creating some hard copy map output from QGIS. I want to use an expression to suppress labels for some features on a layer when another feature from another layer intersects with those features. ...
1
vote
0answers
61 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
559 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
votes
0answers
63 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 ...
4
votes
1answer
292 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
229 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
180 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 multipolygons....
7
votes
1answer
375 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 ...
3
votes
2answers
128 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
27 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
374 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 rice_temperature....