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Questions tagged [intersection]

Use this tag when asking questions related to where features overlap.

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0answers
38 views

Finding overlapping geometries in the same table using PostGIS [on hold]

I have a table containing about 50,000 polygons and some of them are overlapping. I'm trying to use PostGIS to return a table with all the overlapping parts of the polygons along with some of the ...
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0answers
15 views

How to consider current and next year in google earth engine?

I follow this indication to write this script Intersect of raster image on Google Earth Engine My problem: I would like to combine Hansen dataset with other two different maps (b and c) and finally I ...
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0answers
17 views

Check point in line segment not accurate in Shapely

I use Shapely and I've run into an issue where I can find the intersection of two lines. However once I have the intersection point, I don't seem to be able and cross-reference that it belongs in both ...
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0answers
46 views

Using ST_Intersection with three or more tables

I'm trying to achieve a multiple-table intersect with PostGIS while retaining the geom for each shape. For any given property shape, I want individual cuts of that shape split apart by different ...
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1answer
33 views

Calculating the area of one layer inside area of another layer QGIS [duplicate]

I am currently looking at some Marine Protected Areas (MPAs) in Madagascar, and am trying to work out the percentage reef cover inside an MPA boundary. For example (in the picture below), I have the ...
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1answer
22 views

Intersection of two sets in openstreetmap to find parent of any area

I am trying to determine what the parent administrative area of any given area. The idea is that the closest parent is the administrative area with the highest/deepest admin_level that is shared as a ...
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1answer
76 views

How to find lat/long of point knowing cross track distance

Knowing lat/long of point A , B and C. And knowing cross track distance (CTX) from point B to point D. How to find lat/long of point D?
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0answers
34 views

Selecting only coinciding points

I have a lot of points in the same layer. Many of these are coinciding. I only want the points that coincide slected or the points that don't coincide (then I can just reverse the selection). This is ...
3
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1answer
121 views

Use intersection in field calculator

I want to use the tool intersects in the field calculator. If the condition is true, I want to set a result field to a specific number. The field calculator doesn't accept my expression but I can not ...
2
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1answer
117 views

Fast intersection of a list of polygons with a bounding polygon using Shapely

I have a list of Shapely polygons which I need to find the intersection of each with a bounding Shapely polygon. Not all the polygons in the list cross the boundary of the bounding polygon so I only ...
2
votes
1answer
52 views

Getting the percentage area of intersecting polygons [closed]

I have the polygons for census tracts within New York City. I also have the polygons for the parks. What I would like is % of the census tract area, with an added 400 meter buffer, that is park. I'm ...
2
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1answer
30 views

return only one value per point from ST_Value() - currently returning 2 values for some points

I'm testing a point sample query with a subset of 5 points on a single band elevation raster. Using my usual approach (which I've previously not noticed this behavior), I get six records returned: ...
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0answers
45 views

Python script creation, intersection Points and polygons [closed]

I have these two shapefiles, one with polygon geometry and the other with point geometry, that I am working on in QGIS. I want to create a script using Python to see the intersection of points and ...
2
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1answer
39 views

Check 2 Extents with Disjoint in Arcpy - Wrong Result

I'm now facing a problem using Disjoint in Arcpy to check if 2 extents are intersected. I have 2 extents like this: Ext1: 33206887.500051 5890587.49999999 33460887.500051 6060887.49999999 NaN NaN ...
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0answers
15 views

Adding vertices to polyline [duplicate]

I have a polyline shapefile with multiple features. I also have a point shapefile containing only points that are on the lines. What I'm trying to do is to add a new vertex to every line where it ...
2
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0answers
21 views

T-SQL Invalid Geometry Created by Intersection

I have two sets of geometries (A and B) in SQL Server 2016. I want to determine the overlap areas of those geometries from set A that intersect set B. Most of the time this code works: SELECT a....
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1answer
50 views

Styling road intersections

I have two layers with roads of different types I wish to have pretty intersections, as here Symbol levels work only for features in single layer.
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0answers
40 views

How to update column based on data from another table (Mapinfo Pro)?

What I want to do is update column (Table A) by values from another table (Table B) using condition intersects. There are few objects in table B which intersects one object from table A. When I try to ...
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2answers
35 views

Identifying which lines cross building polygons using ArcMap?

I have the following lines generated from coordinates with XY to Line. I would like to select and delete the lines which cross and are contained within the buildings. I need to do this to find the ...
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1answer
31 views

How to snap to intersection of lines with Classic snapping?

The question is as simple as the title. When I am in Edit session with Classic Snapping enabled and want to snap to an intersection of lines, it does not work. In order to achieve this, I have to ...
2
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2answers
83 views

What is the proper name for the “Venn diagram” of a set of geometries?

Sometimes, you have a set of overlapping geometries, and you want to generate an output like this: Image taken from this answer. The resulting polygons have no overlaps; each region of space is ...
3
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0answers
46 views

Unable to compute intersection between two polygons using PyQGIS?

I have two polygons in different layers. I am trying to find the intersect between the two polygons. Below a figure showing my test case. I initially wanted to find the intersect between the green ...
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0answers
15 views

Deleting vector layer within buffer? [closed]

I am trying to delete points from a shapefile with vector information that intersect a buffer that was created. I have tried using the intersect tool, but that only highlights the information that ...
0
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1answer
75 views

Intersect of raster image on Google Earth Engine

I have this situation on Google Earth Engine: 3 different images, each of these are made by 17 different bands. These bands represent the different year. I call these images with these letter: a,b ...
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1answer
36 views

Filter four features from a vector shapefile to create a new layer to perform buffer, intersection and union on it, in QGIS 2.18?

From a dataset that contains points of interest defined by type of object with four different features, I am trying to distinguish the features to perform different analysis. Thought I had to filter ...
3
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0answers
76 views

Intersection and area calculations in geographic vs. projected coordinates

I think one should do intersection calculations when layers are in the same coordinate system, and one should do area calculations in the appropriate projected coordinate system. The order matters, ...
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2answers
66 views

Faster alternative to `Intersection` in QGIS to just retain overlapping features without cutting

I want to keep only the features from my data layer (polygon A) within my area of interest (AOI). If I compare two methods to perform that, the processing time is very different. Intersection tool I ...
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1answer
44 views

Why does shapely intersection of two lines change behaviour when fiona module is imported?

I am having issues with calculating an intersection of two LineStrings using Shapely. Such an intersection should return a point, yet my code returns a LineString. I found a simple example of an ...
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0answers
24 views

How to output file with all overlaps between two Shapefiles - Neighborhood/Zip Codes [closed]

I have a pretty specific problem I would like help with. I have two shapefiles: neighborhoods from https://www.zillow.com/howto/api/neighborhood-boundaries.htm zip codes from the census bureau: ...
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0answers
68 views

Comparing speed of Spatial Analysis with GeoJSON versus shapefile in QGIS?

I have a large dataset that I want to perform spatial analysis on in QGIS. Specifically, I want to perform a polygon intersection analysis between two polygon layers. Given the size of the dataset ...
1
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1answer
81 views

How to find intersection polygons in single layer on QGIS version 3.4.2?

I have polygons intersection in single layer. I want polygon in yellow frame and use polygon intersection to calculate area , how to do this?
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0answers
70 views

Query for finding intersection points between adjacent features within a buffer tolerance - PostGIS

I've developed the queries to find out intersection points (within 0.2 buffer) between line and polygon and also within adjacent polygons by using PostgreSQL 10 and PostGIS 2.4 database. Line data is ...
1
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1answer
41 views

PostGIS ST_Intersects result is ignored by where condition

I have a simple query filtering by st_intersects function finding all lines intersecting with a polygon. select *, st_intersect(graph_line, st_geomfromtext('POLYGON((261 156,148 452,333 507,566 199,...
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1answer
76 views

Extending a segment in QGIS to check intersection with a polygon

I am trying to find the adress points (red dots) located in front of an obstacle (red polygon). The street is green and the pink line represents the street face (Si). This is what I have so far, but ...
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0answers
188 views

Geopandas KeyError: “['__idx1' '__idx2'] not found in axis” during overlay operation

I'm trying to get the intersection area between two geodataframes using the overlay method. gpd_df1 = gpd.read_file("shapefile1.shp") ## US census tract shape file gpd_df1 = process(gpd_df1) ## ...
1
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1answer
65 views

No output of simple intersection in QGIS / Shapely

I have three simple geometries (download): 1) Province boundaries of a province in Egypt (Al Wadi Al Jadid). 2) A 10 x 10 degree polygon (index = 417). 3) another 10 x 10 degree polygon (index = 416)....
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0answers
104 views

Is PostGIS faster than Shapely [closed]

I've recently tried using Shapely to dissolve and intersect large sets of 100'000+ geometries, some of them quite complex. This would take me at least one hour, at which point I would usually shut the ...
2
votes
1answer
52 views

Intersection of touching geometries returns a polygon

I'm using Postgis 2.3. I have two touching geometries that I got from an overlay (ST_Difference) operation: id | st_astext 3 | MULTIPOLYGON(((0 -2,0 ...
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0answers
23 views

Which polygons intersect rectangle in PHP/Linux GDAL?

I'm developing a website where I want to test which polygons from a shapefile intersect a given rectangle. Using PHP, I thought about using exec() function, calling a GDAL program, like ogrinfo. ...
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votes
1answer
16 views

Adding field of intersected polygons in points using ArcGIS Desktop? [duplicate]

I have some points and polygons in an area. I want to add a field in those points that tell what polygons have been intersected by those points and not only what polygons but a specific attribute of ...
1
vote
1answer
54 views

Creating a new shapefile from points which are overlapped by polygons PyQGIS3

I want to extract points which are overlapped by polygons to a shapefile with PyQGIS. I typed the code below, I don't get an error, but I get points that I have on the beginning. So my intersection ...
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votes
1answer
44 views

Calculating wetland coverage/overlay over parcels of land? [duplicate]

I have two layers. Layer 1 has features that are property/parcels with area in acres. Layer 2 has features that are wetlands/bodies of water with area in acres. I want to calculate the percentage of ...
2
votes
1answer
144 views

Slow PostGIS line intersection even with indexes

I have line data contained in different graphs. Querying data over multiple graphs and using st_intersects results in slow queries. All lines are represented as geometry(LineString). I am querying ...
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0answers
142 views

using st_join for a spatial join

I am using the sf_package to work around spatial data in r. At this stage, I want to make a spatial join so that the tax lots of my area of study inherit the attributes of the floodplain on which they ...
3
votes
1answer
59 views

How to flatten spatially equal polygons in PostGIS?

I have the following dataset of polygons. All the pieces are broken based on their borders. I added some transparency to better understand what's going on. The pieces that have stronger colors, means ...
5
votes
1answer
211 views

Only union/dissolve intersecting features to save time?

I have one table of about 300k polygons, some intersecting but most do not. I need to dissolve the intersecting ones and also keep the non-intersecting ones. I only need the geometries, no attributes. ...
0
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0answers
37 views

Shapely intersection operation gives non-intersecting results

I generated two lines by calculating the intersection of each of two overlapping Polygon objects with an overlapping LineString object that goes through both. In pictures: Here is the code: src = ...
2
votes
1answer
78 views

How to trim road end at the intersection?

I have a road centerline that I have used to create buffers that represent road area. Now I need to fix the intersections. As you can see on the picture, if the road end is touching the non-end of the ...
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2answers
40 views

Breaking lines in PostGIS?

I have a roads table and I want to break the lines in the intersections like the v.clean tool from GRASS (I'm talking about how the break tool in the parameters works). How can I do the same process ...
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vote
2answers
44 views

Python script tool to make intersection points not working?

A colleague made a ArcPy tool for me which worked last year, but now it wont complete. I don't know what's different except maybe I moved the tool or it's output to a new location. It say's it get ...