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.
1,815
questions
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Direction of lines in relation to coastline
In ArcMap 10.7, I would wish to calculate an orientation of some linear off shore features in relation to the coast line. I don't really want to create a classic wind/rose diagram in relation to North/...
- 11
0
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0
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30
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Saving a GeoJSON file with UUID [closed]
I would like to save a .geojson file with a geometry information as well as uuid column.
The .geojson file is saved successfully when it has no uid column but when I add a uid column i get an error (...
- 419
2
votes
1
answer
75
views
Generating offset line from MultiLineString in QGIS
I have a MULTILINESTRING in my CSV file, and I want to generate a copy of it offset to the right by a few meters. I've run Single Sided Buffer, and Offset Lines, and neither of them seem to generate ...
- 217
2
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0
answers
34
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QGIS converting MultiPolygon to MultiSurface - can I disable QGIS from doing this?
I have MultiPolygon data stored in a PostgreSQL DB (13.9) and am editing this through QGIS (using 3.28.3-Firenze). Occasionally when editing, some features are saved back as MultiSurface features. ...
- 21
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1
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27
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How to find if a point feature is snapped to a line using ArcObjects
Background to the problem:
When I use the Editor Split tool on a line, the line gets split into 2, and a junction is placed between the two lines. When I use the Editor merge tool, the 2 lines are ...
- 614
0
votes
1
answer
26
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Error in gpd.join related to 'PyGEOSSTRTreeIndex'
I have an error related to gpd.sjoin which shows as follows
NameError: name 'PyGEOSSTRTreeIndex' is not defined
Here is the code:
alltitresQuartiers = gpd.sjoin(left_df=transactions_located, right_df=...
- 419
0
votes
1
answer
62
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Calculating distance between two points on line string
I have a line string and two points with me. I need to understand how to calculate the distance between two points along the provided line string. Also, note that in some cases, the provided points ...
0
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1
answer
16
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City Suburbs Polygon using OSMNX
I am trying to do something similar to the question OSMNX - City Suburbs Polygons. The city of Panama, in the Republic of Panama, is composed of corregimientos (like a borough). I am trying to get the ...
6
votes
2
answers
96
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Is there a common method for measuring "curviness" of a line?
I have a bunch of GPS tracks in a Postgres+PostGIS database and want to extract a single metric as a measure of turns shown in the data. Some of the GPS targets travel in almost straight lines while ...
- 1,505
1
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1
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43
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How to extract polygon attribute based on point location using QGIS expressions
I'm using QGIS 3.34. I have a point layer that contains a single point showing a site location (called "Site Location"). I have a polygon layer covering the UK with 12km squares containing ...
- 609
2
votes
1
answer
69
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Multiple operations within Field Calculator using the same IF statement
I have 2 layers (Point_Orien_Vert - red points and Point_Centroides - green points), both are Point Geometry.
I need first to check if the distance between one feature in Point_Orien_Vert and one ...
- 33
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0
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40
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QGIS Convert Polygon ZM to Polygon
QGIS Convert Polygon ZM to Polygon
Received files that have Shape > PolygonZM I need to attach to Polygon. QGIS: Geometry >< Polygon (MultiPolygonZ)
I managed to get it to Geometry >>&...
- 1
0
votes
1
answer
22
views
Apply Edits on ArcGIS not updating geometry
I am using this command on ArcGIS
curl --location 'https://services8.arcgis.com/xxxx/arcgis/rest/services/SM2/FeatureServer/0/applyEdits' \
--header 'X-Esri-Authorization: Bearer ...
- 101
1
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35
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How QGIS's "Remove duplicate nodes" actually works
I am working on digitizing a large number of polygons using stream digitizing, which sometimes creates duplicate nodes. I noticed that in "Layer Properties>Digitizing>Automatic Fixes" ...
- 11
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0
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27
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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?
- 13
3
votes
1
answer
129
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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 ...
- 419
6
votes
5
answers
493
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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
0
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0
answers
31
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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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1
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0
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31
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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 ...
- 665
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1
answer
152
views
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": "...
- 561
0
votes
1
answer
142
views
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
votes
1
answer
104
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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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1
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61
views
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 ...
- 1
1
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0
answers
70
views
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 ...
- 11
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0
answers
44
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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 ...
- 1
3
votes
2
answers
124
views
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. ...
- 459
0
votes
1
answer
119
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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.
...
- 161
4
votes
2
answers
238
views
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
75
views
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));
...
- 71
1
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0
answers
93
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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 ...
- 11
1
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0
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44
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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 ...
- 11
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0
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34
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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 ...
- 1
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1
answer
76
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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, -...
- 15
1
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1
answer
70
views
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)) ...
- 143
-1
votes
1
answer
270
views
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 ...
- 9
1
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0
answers
53
views
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
0
votes
1
answer
96
views
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
-1
votes
1
answer
153
views
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 ...
- 7
2
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0
answers
62
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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 ...
- 21
4
votes
1
answer
63
views
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
1
vote
2
answers
110
views
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]
...
- 113
0
votes
1
answer
67
views
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 ...
- 161
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0
answers
29
views
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
votes
0
answers
108
views
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) = ...
- 131
6
votes
3
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241
views
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 ...
- 63
4
votes
1
answer
137
views
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 ...
- 93
4
votes
3
answers
222
views
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.
- 605
-2
votes
1
answer
119
views
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 ...
- 189
0
votes
1
answer
59
views
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
97
views
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 ...
- 3,715