Questions tagged [geometry]
(1) abstract geometry; (2) storing geographic data in projected coordinates; (3) a generic ESRI term for vector features; a class for "geometry" objects.
1,800
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Mapping Post Codes from form records Survey123
I'm a student with little experience in ArcGIS generally and used Survey123 to create a questionnaire and collect responses for my Geography Coursework.
I accidentally published the survey with the ...
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0
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16
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How to fix the error in GML: non-planar polygon distance
I have validated the GML data in the CityDoctor. It found the error "GE_P_NON_PLANAR_POLYGON_DISTANCE_PLANE" in nearly all of the buildings. Is there a short way to fix such an error?
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3
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1
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85
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From Geodataframe to PostGIS
I have a geodataframe which I am trying to save to a postgis database.
I have already created a connection to postgis in pgAdmin (username, password, localhost and table)
from geoalchemy2 import ...
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13
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TypeScript packages that can help validate a geometry object before saving in MySQL database [closed]
Currently, I use the booleanValid function from turf to validate a geometry object before inserting it into the database.
Upon testing, I found scenarios where it doesn't correctly check if a loop is ...
6
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5
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418
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Finding overlapping polygons within the same layer in QGIS
I have a polygon layer and want to check if there are some polygons overlapping within the same layer. How can I do this?
In ArcGIS, I could run the Intersect tool only by adding the layer I want to ...
- 414
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20
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Error in projecting a shapefile from CRS of ArcMap to a Proj4 string
I am trying to export the outputs of the National Water Model (https://github.com/NOAA-Big-Data-Program/bdp-data-docs/blob/main/nwm/README.md) inside of a basin using Python.
With this code I called ...
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30
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ST_COVEREDBY passes using geometry but fails with geography
I have a table of points and a table of polygons in PostgreSQL 11.18 and PostGIS 2.4.4. Both use Geography SRS 4326.
CREATE TABLE my_points (
id integer generated by default as identity,
geom ...
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1
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45
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Reading single feature as dict into GeoDataFrame with GeoPandas
I have a Leaflet map where a user can select a feature and be able to download some data for that feature. I'm getting the object like this to pass to Python:
data = {
"type": "...
- 531
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votes
1
answer
67
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Read GeoJSON object in a CSV file column and transform it to geometry
I have a column ('geo_shape') that contains GeoJSON object type of linestring geometry and, so far, I didn't manage to read and transform it to a GeoPandas/shapefile type of geometry.
Here is a way ...
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4
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1
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83
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PostGIS: Convert geometry type from MultiLineString back to LineString
I am working with a PostGIS database where I want to alter the geometry type from MultiLineString to LineString. My table used to be a LineString, so I know that all lines are simple, single line ...
- 659
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41
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Generate lines from given azimuth and points in GeoPandas
I am reading a points shapefile containing the azimuth information in the attribute table, and I want to generate lines from these data. I have tried to use shapely.Point as a tool, however it can't ...
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64
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Calculating the surface area of the ocean at each latitude
I am trying to get the surface area of the ocean at each 1° latitude slice. However, for some unknown reason, region -61 which is at latitude -61 has a negative number, and am not sure why that is the ...
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27
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Transformation needed for placing cartesian coordinate rectangle on map using geographical coordinates
I have come across a requirement to convert rectangle image with specific width and height to geographical coordinates so that it can be placed on map. I have all the four geographical vertices for ...
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3
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2
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110
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Unifying touching polygon within polygon geometry in PostGIS
I have a polygon geometry with 100+ polygons originally converted from a raster table - see the below image
Zoomed view of one of the polygons
I would like to unify the touching polygons (i.e. ...
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1
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72
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Alternatives to Compute Pole of Inaccessibility in Python?
I discovered the other day that Shapely's current implementation of the polylabel algorithm for approximating a polygon's pole of inaccessibility does not always produce a point within the polygon.
...
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71
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Import JSON file as table in Excel and visualize polygon geometry using ArcGIS plugin for Excel
I have a quest where I have to visualize the polygons in my local disk in Excel using ArcGIS plugin. Based on what I understand, I can only import it as a JSON file from the get data panel, but the ...
3
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1
answer
143
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Smoothing corners in polyline using PyQGIS
I have an array of QgsPointXY that makes a line with lots of vertices.
How can I round the corners?
Here is what I mean:
The code is:
def __round(line: list[QgsPoint], radius: float) -> ...
4
votes
1
answer
66
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Deleting NULL geometries and duplicate nodes from table using PostGIS
I run the command to delete null geometry from a table:
delete from table where geom is null
And delete duplicate nodes by running the command:
update table set geom = ST_Multi(ST_Simplify(geom,0));
...
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1
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50
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How to find the coodinates of a new bounding box from four circles present with known radius around the vertices of an existing bounding box [closed]
I have a bounding box which I have created. I know the lat lon of the four vertices of the box. On these vertices I have created a buffer circle of radius 10m and now I want to calculate a new ...
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43
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Viewing source query/code of the plugin "Check Geometries" in QGIS
I am running a plugin "Check Geometries" to determine the topology errors. It's running smoothly. But I want to have a SQL or Python query out of the executed process. For all other tools ...
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24
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Landsat 8 geometry of image
I'm trying to find actual geometry of the Landsat 8 image.
I retrieve Landsat data from ONDA service using EODAG. Onda provides Landsat 8 images in TIF files in epsg:4326. And it looks so:
Also, in ...
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36
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DISJOINT and TOUCH between Polygon and LineString not working as expected in Oracle Spatial
I have the following 4 geometries in an Oracle Spatial table:
A) POLYGON ((-100 40, -100 44, -96 44, -96 40, -100 40))
B) LINESTRING (-99 37, -99 40)
C) POINT (-100 41)
D) POLYGON ((-96 41.5, -95 42, -...
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53
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Can I use WGS 84 and geometry calculations to check if a point is inside a polygon?
I'm storing polygons in a PostGIS database. The shape of the polygons is stored in a field of type geometry(Polygon,4326).
From time to time, I need to check if a point (of type geometry(Point,4326)) ...
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1
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152
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QGIS new versions 3.28, 3.30... One part can not be selected, vertexes too, can't work with multi polygons, One part is "Hole lies outside shell"
I am currently stuck on working with polygons with QGIS versions from the new patches with the new styles (3.28, 3.30, maybe 3.26 too etc...)
When I used previous versions of QGIS, for instance 3.16 ...
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45
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QGIS: multipolygon vector shapefile -> problem to correct latitude
I am currently working with QGIS for my master thesis (without much previous experience).
I was provided with a shapefile containing MPAs (marine protected areas: see picture below).
The latitude is ...
- 11
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1
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74
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Adding polygon geometry to numpy array to plot it with background
I'm trying to plot image I treated in dataframes.
I need to add geometry to it in order to plot it with a background.
I should have used GeoPandas and geodataframes in the first place.
I have arrays ...
- 33
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1
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97
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Get "geometry column" error when importing my csv file on Google Earth Engine through asset tab
I want to localize my plant specimens on Google Earth Engine map by importing a CSV file with two columns, including longitude and latitude, which belong to Quebec province, Canada. After I select my ...
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2
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51
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MultiPolygon - removing polygons intersections in PostGIS [closed]
Having a MultiPolygon, I would like to get a MultiPolygon where each polygon has no 'holes' and there are no polygons intersecting with each other.
How to achieve this in PostGIS?
To give you an ...
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4
votes
1
answer
59
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Grouping features with identical values in two fields and deleteing the geometry with the lowest value in the third field using QGIS
I've got a shapefile with three fields: "X", "Y" and "Z" they are the geometries as well but I also have them as field values.
Every line geometry in the shapefile has a ...
- 41
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2
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74
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Create a longer line segment from a shorter one?
I do not believe my math is incorrect. This is seems like it could be a projection issue.
I start with the following two coordinates ( lon, lat in degrees )
a: [37.821055535000085, -46.84417083099993]
...
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1
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65
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Geometry of recently created point
Description
I am currently working on a project that requires the creation of default values in certain fields when attempting to insert a new feature. This operation is illustrated in the figure ...
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26
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Geometry calculation in ArcMap
I am using ArcMap 10.8.
I have many point (i.e. off-scale) bridges for which it is necessary to calculate the strike azimuth of the symbol.
How can I do this?
I know about the "line bearing" ...
2
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0
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82
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Geometry comparisons in SQL
Newbie to GIS here.
Equality can be defined on a geographic value by seeing if they have a collection of the same points. For example, something like:
-- The equality
-- `LINESTRING(1 1, 2 2) = ...
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3
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230
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Unable to use the tool "difference" after the tool "clip"
I have stumbled on an error and I would like to have an external point of view to maybe help me figure it out.
When I
clip layerA as input with layerB as the overlay, and then
make the difference of ...
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4
votes
1
answer
100
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Removing duplicates geometry rows in PostGIS
I am maintaining a table which has geometry datatype and it's possible that the table can contain duplicate geometries.
If I want to remove duplicate rows or select only non-duplicate one, will both ...
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4
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3
answers
207
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Changing orientation of all polygons at once with numeric value in QGIS
I want to change the orientation of the raster/polygons with a numeric value around the centroid of the total grid.
I have tried rotate($geometry, 45) in the Field Calculator but nothing happened.
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1
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94
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PostGIS: ST_LineMerge can make LineString from MultiLineString [closed]
I am trying to convert MultiLineString to LineString with PostGIS:
This is my query:
SELECT (st_astext(ST_LineMerge( geometry ))) AS shape
FROM public."Cities"
where id = 364087;
but the ...
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1
answer
40
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PyQGIS - draw a line between start- and endpoint using tracing to fit into another line
I have 2 vector layers, "pipes" and "fibres".
The lines in the pipes layer are already drawn.
Now i want to draw a line in the fibres layer from a start point to an endpoint, but ...
- 357
2
votes
1
answer
72
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PyQGIS - modify Z-values for Polyline
I have a GeoJSON file that I have loaded into QGIS as a LineString, and draped over a DEM using Drape (set Z value from raster)
I now want to round the Z-values to 4dp before exporting the modified ...
- 2,465
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46
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Selecting geographically identical (underlying) line segments and offset them in QGIS
My project has three lines representing three routes along town streets. All three routes lie on the same street for part of their lengths; two of them lie on the same street for another part of their ...
- 1,076
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92
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QGIS: Calculate distance between two point layers based on matching ID
I have two point vectors in QGIS. One contains several coordinates, which are grouped geographically by a reference in the field name PID.
I also have a point vector of the centroids from each group ...
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386
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Generate WKT from geometry type in SQL Server
I have a bunch of polygon data in a SQL Server database.
Most of the data was created in Google Earth and exported as KML, then imported to SQL Server as WKT before conversion to geometry.
Each record ...
2
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1
answer
140
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Refreshing/using active geometry bounds using Google Earth Engine app-side for data export
This is my first time posting here, so bear with me. This is a continuation of the response to this question, but I don't have enough reputation to comment.
I am working on this GEE Web App where the ...
0
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2
answers
410
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Check geometry type of shapefile with GeoPandas
Using GeoPandas, how can I check the geometry type of a shapefile (i.e. Point, LineString, Polygon etc).
I can use the following to check the geometry type of each feature but this is unnecessary, I ...
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Reconstruction of a geometric graph: link only vertices with no vertices in-between [closed]
I'm a mathematician who got lost here looking for the name of a graph construction.
Sorry if my question is silly/out-of-topic, but it seemed like a good place to ask.
I hope my notations are going to ...
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10
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131
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Merging layers and excluding some of the products in QGIS
When merging two layers of polygons so that they produce a third layer where no polygon contains another polygon, I find that the product contains some very small polygons, almost too small to see.
...
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6
votes
2
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202
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Categorising data points along transect using QGIS
I have data on the latitude and longitude of several locations in Europe (blue). So far I have been able to read this data into QGIS but not more. I would like to plot a transect (red) and then ...
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4
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157
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How to join geodataframe itself
My goal is to calculate the distance from a point and the nearest point, so I thought of using geopandas function sjoin_nearest. Using this function I get all the distances to zero, which is quite ...
- 209
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88
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Calculate point line distance for a geolocation with altitude
I'm trying to calculate the coordinates (Latitude, Longitude, Altitude) of a point on a line at the minimum distance with another point.
I was able to calculate the distance using the formula here:
...
4
votes
2
answers
149
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Consolidating overlapping and fragmented line into a single line geometry
I have a circular hiking trail. It was digitized in a way that I cannot reproduce. It is apparently a circular path, but it consists of many individual parts that overlap completely or partially. Also,...
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