Questions tagged [well-known-text]

Well-known text (WKT) is a text markup language for representing vector geometry objects on a map, spatial reference systems of spatial objects and transformations between spatial reference systems.

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Languages to represent ellipse geometry (WKB/WKT)

I am new to the idea of representing vector geometries in a text markup language. I am looking into different representations for geometries consisting of smooth curves and three dimensional objects, ...
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Why do single-part WKT polygon vertices require double parentheses?

Regarding the WKT standard: Wikipedia: Well-known text representation of geometry Why do single-part polygon vertices require double parentheses? That seems inconsistent with single-part points and ...
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Adding wkt.csv file to QGIS 3 project using script

I have written a plugin using the Plugin_Builder tool. It takes a CSV, rearranges it and adds a column of WKT coordinates in the style LINESTRING(x1 y1,x2 y2). It then writes it as a new .csv. This ...
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LRS SDO_GEOMETRY to "LINESTRING M" WKT format

I have a query that produces an LRS SDO_GEOMETRY as WKT (Oracle 18c): select SDO_UTIL.TO_WKTGEOMETRY(SDO_LRS.CONVERT_TO_LRS_GEOM(sdo_geometry('LINESTRING(1 2,3 4)'))) from dual Output: ...
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Strange white filling of new added Vector layer in OpenLayers map

I generated an OpenLayers map project using the qgis2web plugin. I would like to add the new Vector layer using the WKT polygon geometry. In the following code geomLine is WKT Polygon. Nevermind, when ...
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QGIS rotate CRS around a new centre

I've been given some NetCDF data in a Mercator projection with a centre longitude of 173.9581, centre latitude of -41.0870 and rotation of 40 degrees. I have tried to create a new CRS based on ...
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Obtain CRS compliant WKT from GeoPackage with ogrinfo

I would like to obtain the WKT for a few geometries stored in a GeoPackage file with orginfo. That is the function of the -al parameter. However, when applied directly to the file in question it ...
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1 answer
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Spatialite: insert points, do knn search. how to?

So I want to add 20 points, run Spatialite knn and find 10 points. I created a simple test in colaboratory: import os from datetime import datetime import json from pprint import pprint from playhouse....
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2 votes
2 answers
52 views

FME GeometryReplacer, WKT Error

I am trying to load POINT WKT Geometry from MS SQL Server, it is in WKT Format. Using the GeometryReplacer, I am receiving an Error, and everything looks right as far as I can see, it continues to ...
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3 votes
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Create custom CRS modifying an existing projection (e.g. Robinson) on QGIS

I'd like to create a custom CRS that meets some requirements I need for a project. I've spent a lot of time looking for all existing projections consulting for example this site: https://map-...
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How to set the scale bar correctly in print layout

In the print layout, the layer uses custom projection, and the correct scale cannot be set. I want to use kilometers as the scale bar, but this custom layer can only use map units as the scale bar, ...
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Converting dataframe with WKT column to spatial dataframe in ArcGIS API for Python

I am querying a data set from an Oracle spatial server with the geometry field in a WKT format, and I am running into issues trying to convert it to a spatial dataframe using the ArcGIS API. Going ...
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Changing the naming of a coordinate system in QGIS

For compatibility reasons with a different software I need to change the naming of a CRS in QGIS (ETRS89 / UTM zone 32N). After georeferencing a file in QGIS I would like the CRS to show up in the ...
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2 votes
4 answers
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Converting OGR geometry as WKT of polygon from float to integer in the WKT string

(This is a repost into this community of my original question posted on SO, because there has been no answer so far. Hopefully in this community more luck. I'll ask for the other one to be closed.) I ...
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1 answer
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Converting a WKT column to type Geom

I have the following table in my MariaDB database: This table contains a column called 'coordinates' (type: LONGTEXT) with a wkt representation of either a MultiPolygon or a Polygon. I am attempting ...
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3 votes
1 answer
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Mime type for WKT?

What is mime type for Well-known Text (WKT)? text/wkt?
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2 votes
1 answer
134 views

QGIS show WKT from attribute table

I have a dataset (from mysql) which I can load into QGIS. One of the columns in the table (and thus in the attribute table) is a WKT column. I am not able to select this column for the geometry. The ...
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1 vote
1 answer
144 views

Can we construct WKT2 from PROJ4String correctly?

There is the new WKT2, with great features, but there is a lot of data saved in WKT/PROJ4String too. The docs I read say the PROJ4String doesn't have enough info for a complete reference for ...
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Converting LINESTRING wkt representation LINESTRING((a b),(c d)) to LineString[(a,b),(c,d)]

I know how to go from line = LineString([(0, 0), (1, 1), (2, 2)]) to LINESTRING ((0 0), (1 1), (2 2)) But not the other way around. How do I do this? The reason I need to do this is that I want to ...
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What is a SHN object and how to convert it into a polygon?

I have a dataset with a georeference called SHN that corresponds to a 12-digits number. For instance, the area Gemeinde/Stadt: Stadt Lauingen (Donau) is identified as 097730144144. What does SHN stand ...
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-1 votes
2 answers
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Where to find the WKT of a particular co-ordinate system

I'm using ProjNet in my C# application for coordinate conversion that requires WKT of source and target co-ordinate systems. I have googled but didn't find the WKT of MGA2020 Zone 46 [EPSG 7846], ...
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1 vote
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Choosing vector source format for geospatial dashboard [closed]

I'm currently working on a Geospatial dashboard application where I have base maps and raster data in polar-centric projections, using open source tools (GDAL, PostGIS, OpenLayers). In past projects, ...
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3 votes
2 answers
407 views

Convert string of coordinates to WKT for import into QGIS

I have a CSV file with a field that is in the following format Latitude Longitude Altitude Accuracy, Latitude Longitude Altitude Accuracy [etc] e.g. 51.1 -4.2 100 5, 51.2 -4.1 110 5, 51.1 -4.1 200 10 ...
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1 answer
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Difference between notations of WKT format: 'POINT()' and 'Point ()'

After reviewing this thread Adding field with geometry in WKT format in QGIS I started to wonder about the difference between the WKT notations: 'POINT(276547.16725324 5477265.87268898)' and 'Point (...
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1 answer
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ProjNet4GeoAPI calculates with mistake

I need to convert from one geocs to another. I took wkt strings from https://spatialreference.org/ref/epsg/4284/ and https://spatialreference.org/ref/epsg/4326/. Code is dead simple: string ProjSk42 = ...
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1 vote
1 answer
118 views

Automatically running an ST_AsText query over multiple rows in QGIS

After my SpatiaLite database got corrupted, I used a recovery tool to recover what was lost. I now do have the database, but I can't visualise the features on a map. I figured out that with SELECT ...
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1 vote
1 answer
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Creating Python OSGEO/OGR geometry with M-values (not using WKT)

I am trying (and failing) to generate M-value geometries (e.g. POINT M, POINT ZM, LINESTRING M, ...) with Python's osgeo/ogr library. Here is what I've tried to far: import ogr # Use OGR specific ...
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1 vote
1 answer
263 views

How can I use the Python osgeo/ogr library to export a feature layer to CSV with geometries coded as WKT?

How can I read in a layer's data using the python osgeo/ogr library and then export the whole attribute table and an extra column with the geometries coded as WKT to a CSV format? I know that this is ...
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1 vote
2 answers
210 views

Python-PDAL: error reading Format 1.4 LAS File - (readers.las Error) Global encoding WKT flag not set for point format 6 - 10

I am using python-pdal 2.4.2 to read a LAS 1.4 in PointFormat 8, with the objective or using different writers stages afterwards. The pipeline is simple: import json import pdal filepath = "path/...
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0 answers
29 views

Converting base64 encoded geometry to WKT

An element in a received XML-file contains the geometry, which I believe is base64-encoded: <pointData>...
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0 answers
51 views

Problem with getting irregular polygons from WKT data

I am quite new to QGIS, and am working with air pollution survey data from ODK. I have to correct the survey inaccuracies (in the WKT coordinate data) recorded by using satellite imagery as base layer....
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2 votes
1 answer
139 views

QGIS Custom Projection in WKT not saving .prj file

I've created a Custom Projection System in QGIS using the WKT format (see code below). The custom projection using a local grid system and transforms it GDA94 / MGA zone 51. It works well in QGIS to ...
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5 votes
1 answer
228 views

Where are the WKT types CIRCULARSTRING, COMPOUNDCURVE etc actually defined?

I'm trying to find the actual definition of the curve types supported by PostGIS in WKT. PostGIS's documentation refers to the " SQL Multimedia Applications Spatial specification": The SQL ...
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0 answers
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JavaScript libraries for converting curves to/from EWKT and GeoJSON

Are there any JavaScript libraries that can convert EWKT/WKT curve geometries (as defined by PostGIS) to GeoJSON or similar? That is, libraries that generate a linear approximation of a CIRCULARSTRING ...
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1 vote
1 answer
45 views

How does QGIS reproject data onscreen when the project CRS is geographic?

From what I understand any dataset (GCS or PCS) in QGIS must be "reprojected on the fly" according to the project CRS when viewing the data as a map onscreen. So my question is what type of &...
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-2 votes
1 answer
153 views

Creating shapefile from CSV file with geometry in WKT [closed]

I would like to get some help creating a polygon shapefile using a CSV (geometry). I have copied the first few rows. I use ArcGIS and a little bit of QGIS. Step by step give will be very helpful, I ...
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0 votes
1 answer
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List supported WKT spatial references in GDAL, c++

I would like to ask if I can retrieve a list of supported projections from GDAL API. I am trying to use GDAL to coordinate transformation for my internal data in the following way. struct MyConverter {...
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2 votes
1 answer
44 views

"Perforated" polygon voids are filled when using OpenLayers with WKB geometries

When I try to draw a "perforated" polygon using GeoJSON.readFeatures() the "solid/void" relationship is drawn correctly, the void parts don't have any fill color. See the example, ...
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3 votes
0 answers
59 views

How to properly convert from WKT to euclidean 3d points?

I am not a geoscientist (I do computer graphics), however I am trying to render some geospatial data encoded as a WKT file. I have a POLYGON with 2 coordinates per point, which seems to be ...
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5 votes
1 answer
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Difference between LINESTRING((x1 x2), (x3 x4), (x5 x6), (x7 x8)) and LineString([(x1,x2), (x3,x4), (x5,x6), (x7,x8)])

I am a little confused about how objects are being defined and represented and mostly because some of the solutions I find for solving issues I have demand that the input data be in an other form than ...
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1 vote
1 answer
290 views

STContains, STIntersects and STWithin return wrong result for geography loaded from WKT

I'm trying to determin whether a point is within a polygon. I created a polygon a two points with this tool: https://clydedacruz.github.io/openstreetmap-wkt-playground/ Polygon: POLYGON((18....
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5 votes
1 answer
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Changing coordinate of point using its WKT and PyQGIS

I need to change the position of a box only if it has a common attribute with a point. In my example if the feature "ID_PARENT" is the same as "CODE". box = QgsProject.instance()....
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1 vote
2 answers
282 views

Convert WKT Polygon to ESRI Geometry String in Standalone Python Script

I am trying to convert a WKT String like this to ESRI Geometry String. I am looking for a solution that does not require an ArcGIS license. Polygon ((-95.92442111883893574 30.18765532529553752, -95....
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1 vote
2 answers
160 views

Cannot verify WKT polygon for use with SQL Server geometry

I am trying to create a polygon, with inside cut out, and I have created a dozen of them no problem. However, I cannot get the following point list to verify. POLYGON( (53.890253 -114.150550, 53....
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1 vote
1 answer
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Is my WKT projection definition wrong or is there a bug in PROJ?

I'm using PROJ with a WKT projection string to try and match a coordinate system being employed in a 3rd party solution. I seem to be able to match the 3rd party coordinates when projecting EPSG:3857 ...
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  • 485
0 votes
2 answers
558 views

Finding an EPSG code for a LiDAR file given only its metadata

I am working with v1.4 .las files from El Paso County, CO, that individually appear without any reference to their projections (none that R sees, anyway). From the metadata I can see the following ...
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0 answers
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Add new spatial reference to ArcGIS with WKT

I'm working with a layer on ArcMap with a spatial reference that is not included in ArcMap. How can I create and add the spatial reference because I already know its WKT? I use ArcMap 10.3
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2 answers
39 views

Compare multiple projection strings to shortlist unique projections

I have a list containing multiple projection strings. Each string is unique but there are some string which are same projections despite being different. [ "PROJCS[\"...
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1 vote
1 answer
105 views

Two identical geography objects produce different STIntersects results in SQL Server 2019

Consider I have two POLYON geography object, @g1 and @g2. One from WKT and the other one converted from binary: DECLARE @g1 geography = 'POLYGON ((-45.70072144031528 70.79588950876575,-45....
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8 votes
2 answers
599 views

Converting geometry to WKT format by using QGIS Expression

I have a gpkg file and I am changing the geometry to wkt format by using expression geom_to_wkt( $geometry ) in the Field Calculator. The output looks like this in the image. The geometry type is not ...
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