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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1answer
53 views

Lat/Long data to shapefile with many values in CSV dataset

I have my polygon spatial data in a format of CSV with the column of lat/long delimited by comma. Is there any way to upload this csv and got polygon shapefiles (or any other visualisable format)? My ...
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1answer
23 views

R: ggplotting st_cast(“MULTILINESTRING”) lines: ends points connected to starts, undesirably, why?

I have the lat-lon positions of various individuals. When I plot multiple individuals at the same time, I see odd lines over land, and have been investigating why. It transpires that plotting ...
4
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1answer
80 views

lat, lng to lng, lat in polygon WKT - axis flip

I have a sheet with the column with polygon information in WKT format. However, the data taken are from web mapping (OSM or google maps) and in the order of lat, lng. When I am using the solution from ...
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1answer
35 views

Polygons with WKT extension load extremely slow

I am quite new to QGIS. I have temporal data per month for the period of 8 years for all Indian districts (+/- 650 districts). This means I have approx. 65.000 objects in my attributes table. Once I ...
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1answer
56 views

Export/convert Points to Polygon

I have to convert a .shp into a .csv file and upload it to the SQL Server, for a program that only supports Polygon format and can not render Points. Is there a way to convert Points to Polygon or is ...
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3answers
160 views

Is there an alternative to prj2epsg.org?

In the past, we used prj2espg.org to find the srid/espg code from .prj file of shapefiles in order to import them in PostgreSQL. Unfortunately, the website seems to be down since November 2019 (...
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0answers
29 views

Converting a description of polygon with arcs to WKT

A document that I am trying to digitize contains descriptions of polygons (see below). The descriptions are converted to WKT for a backend. However, I get stuck at the "along (counter)clockwise ...
5
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1answer
59 views

Maximum character length in Well Known Text for QGIS

Is there a maximum limit of characters in an Well Known Text (WKT) that allowed by QGIS Desktop?
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1answer
43 views

WKT coordinate inner order (long,lat)

In an open-source tracking project that uses WKT in its API, we have a debate about what is the correct order for representing geographical coordinates. Lat and then Long or Long and than Lat. In most ...
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1answer
39 views

OpenLayers: Incorrect rendering of WKT

I'm using the draw function of OpenLayers for draw a polygon. I need the wkt from the drawn geometry because I need to send it to PostGIS. <textarea name="name" rows="20" cols="80" ...
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1answer
18 views

Trouble working with a .TSV containing WKT

I'm working with a .TSV file that represents district boundaries in a portion of a country in Carto. The polygon data is represented in a string column of Well-Known Text lat/long vertices, which I'm ...
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1answer
73 views

Convert points to line segment

In MySQL, I have two tables to store GPS trackpoint and second table to store chainage values. Lines can have more than one condition. I wish to generate line segments by using both tables above. ...
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0answers
74 views

Convert list of GML coordinates into WKT

I am working with a NetCDF file. One of the attributes of the file is its footprint given as just a list of GML coordinates e.g. #ncds is a netCDF dataset >>> ncds['METADATA/EOP_METADATA/om:...
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2answers
49 views

Coordinates of WKT in PostgreSQL

I have a table in PostgreSQL. And it has no X and Y coordinates. But, it has a geom column with the WKT. Also, I have created an empty column called LAT and other called LONG. So, what I want is to ...
3
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1answer
166 views

.prj files from ESRI aren't WKT

We are seeing .prj files from our users that don't look like the normal WKT formatted ones we've seen up to this point, instead, they match the format illustrated at "Esri Grid format". When we ...
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1answer
211 views

Create an ESRI Shapefile from WKT with OGR

I want to create an ESRI Shapefile layer from a CSV file. In my CSV I have several attributes (text, numeric) and geometry in WKT style. I have a problem with the geometry field wich is truncated to a ...
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0answers
97 views

Write GeoPandas df to PostGIS - Linestring Z geometry

I am trying to write a geodataframe with Linestring Z geometry to a PostGIS table. This rise the error: ProgrammingError: (psycopg2.ProgrammingError) can't adapt type 'LineString' [SQL: INSERT INTO ...
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0answers
52 views

Generate custom WKT Coordinate System definition from local / WGS84 pairs of coordinates [closed]

I am wondering if it possible to create a custom WKT for coordinate transformations based on pairs of WGS84 lat/lon and the corresponding local N/E values. So like a minimum 2 pairs? If so is it ...
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1answer
119 views

Check if shapefile Polygon has a valid number of points - Python [closed]

I'm trying to create a polygon from ShapefileReader.shapes() object in python using the shapely.wkt library. But I'm having the followeing error: IllegalArgumentException: Invalid number of points in ...
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2answers
88 views

Why is a vertical polygon defined by WKT PolygonZ invalid?

Can you tell me, why this PolygonZ is invalid? PolygonZ ((409662 5317369 285, 409662 5317377 285, 409662 5317377 302, 409662 5317369 302, 409662 5317369 285)) The polygon is completely vertical, but ...
2
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1answer
69 views

How can I determine if a transformation between two CRS is simply scaling/translating or more complex?

We are using pyproj to transform between coordinate reference systems. What is a good way to check if the transformation is simply scale/translate/units? Basically, I want to know if a grid in the ...
3
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1answer
110 views

Pasting more than one geometry at a time in Quick WKT plugin for QGIS

I have a CSV of WKBs that I need to convert to WKT. Can I paste them all into Quick WKT at the same time? How do you break the spaces between geometries? Page break, comma, semicolon, etc. do not ...
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2answers
294 views

Converting SDE.ST_GEOMETRY polyline to SDO_GEOMETRY with SQL: Why are there so many nulls?

I have a SDE.ST_GEOMETRY polyline FC in an Oracle 18c/10.7.1 geodatabase. I want to convert the SDE.ST_GEOMETRY shape column to SDO_GEOMETRY using SQL. Reason: So that I can do linear referencing ...
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1answer
166 views

Use PHP form to insert geometry from WKT into SQL Server 2017

I have a PHP 7.3 form that asks the user for a Name, a WKT and an SRID. I would like to upload the WKT and SRID to SQL Server 2017 so that it creates a geometric object in Upload_WKT_Test using ...
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1answer
92 views

Lat/Long WKT field to line geometry

I'm working with data containing multiple lat/long entries within a single row. I am using PostGreSQL to process the data. Is there a way to take the WKT lat/long field and convert it into a line geom ...
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1answer
102 views

Using geometry stored in SQL Server table instead of WKT as input to function

I am new to SQL Server, I have a function called STVectorize that takes a geometry and breaks it down into its constituent vectors: SELECT e.[id], e.[element_id], e.[subelement_id], e.[vector_id], ...
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0answers
103 views

Can't import WKT polygon to SNAP

I have big size Sentinel-1 image and I would like to clip it to smaller size. For that i'm trying to import shapefile but I get errors all the time: This is my polygon WKT: PolygonZ ((102....
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0answers
107 views

Unknown proj4: how to create custom proj4 from wkt?

I have a shapefile with a .prj file I've never seen before. In fact, it seems that GDAL doesn't even know what it is (see below). Therefore, when I read it into R with raster::shapefile() the CRS isn'...
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1answer
160 views

Convert shapefile to WKT [closed]

I have this : poly1 = ogr.CreateGeometryFromWkt(polygons) and error : Traceback (most recent call last): File "C:\PROGRA~1\QGIS3~1.6\apps\Python37\lib\code.py", line 90, in runcode exec(code, ...
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2answers
1k views

Adding field with geometry WKT in QGIS

I have a shapefile with polygons and want to add an attribute field with the WKT in QGIS 3.4. The function geom_to_wkt in the Field Calculator isn't working and I don't know how to do it. Any ideas?
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1answer
92 views

Calculate feature extent OpenLayers?

I have a feature created from Well Known Text as following: var feature = format.readFeature(wkt , { dataProjection: 'EPSG:25830', featureProjection: 'EPSG:25830' }); When I add it to a ...
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0answers
27 views

Converting feature from draw interaction to WKT string

I've problems with converting the feature which I'm getting in draw interaction into the WKT string. I saw multiple examples which looks like it should be simple but I'm always getting the following ...
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1answer
43 views

Multipolygon in Los Angeles County Parcels Tax Roll

I downloaded the Los Angeles Parcels Tax Roll data into QGIS. I copied the information for a single parcel results in QGIS: wkt_geom OBJECTID_1 AIN Roll_Year AssessorID TaxRateArea ...
2
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1answer
75 views

Converting tabular data with multiline string field using FME?

I have data in a table. One of the fields has pairs of coordinates. The coordinate pairs represent a point and the points joined in order to represent a line. The number of coordinate pairs varies. ...
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0answers
86 views

What could be a proper and simple invalid WKT/WKB geometry?

We are converting a geometry table to another one and we would like to convert every invalid geometry to a single one easily identifiable by users in WKB or WKT form and not breaking the processing or ...
2
votes
1answer
164 views

Convert WKT to image [closed]

Is there any way to convert WKT like MULTILINESTRING ((48.8744070530328 34.71707055692468, 49.127092599907755 34.72892221300337, 48.89363312725153 34.70987407974113, 48.93002533916562 34....
2
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1answer
115 views

Shapefile export of holes geometries in QGIS with wrong type MultiPolygon

I want to export a layer with holed geometries in it. But when I save my features to shapefile in QGIS 3 it creates a file with MultiPolygon as geometry type. The fact is that a holed polygon isn't a ...
4
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2answers
628 views

PostGIS `COPY` geometry with SRID?

Is it possible to use COPY on a file full of WKT POINTs without dropping the explicit SRID on the destination column? I'm trying to insert several million rows of WGS84 points and am using COPY for ...
1
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0answers
64 views

Why coordinates are saved like “0101000020110F00003CDBA337DCC351C06D37C1374D374840” in db? [closed]

On my DB, the data looks like this: In the DAO I am executing a query: public Object login(UserEntity user) { StringBuffer sb = new StringBuffer(); sb.append("SELECT user FROM ...
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1answer
138 views

Custom projection in GeoServer

I am trying to create a custom projection in GeoServer, but I see nothing (from the logs, neither in the SRS_list) coming out. The projection I'm trying to create is a Mercator for Mercury. I start ...
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1answer
271 views

Sending geographic data from Postman?

I am trying to create a GIS app using Java, Spring and Hibernate. I send a JSON from Postman like this: { "pointName":"any location", "geom":"POINT(-71.060316 48.432044), 3857" } The JSON ...
0
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1answer
179 views

Get GeoJSON or simple WKT from a GPFeatureRecordSetLayer ArcGIS js API

Is it possible to get the GeoJson representation of a GPFeatureRecordSetLayer that is returned from GPServer task? I am able to draw the feature on the map (using the ArcGIS js API) with code like ...
2
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0answers
604 views

Implicitly convert Geometry to WKT string in PostGIS

Suppose I have a table defined as follows: CREATE TABLE gtest (name varchar, geom geometry); To insert, I am able to simply do this: INSERT INTO gtest VALUES ( 'Polygon', 'SRID=4326;POLYGON(...
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2answers
314 views

ST_GeomFromText fails on syntax error inside tuple of coordinates?

I am receiving the following error when trying to execute ST_GeomFromText(wkt) psycopg2.ProgrammingError: syntax error at or near "1187780.76" LINE 1: ...0822.05,(ST_GeomFromTEXT(POLYGON ((...
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1answer
240 views

Export MultiPolygon data as WKT from QGIS 3

I have the polygon data for the city of Kamloops in QGIS 3. When I try to copy features of this polygon and try to paste it over here: https://arthur-e.github.io/Wicket/sandbox-gmaps3.html I don't get ...
6
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2answers
636 views

Convert WKT coordinate reference system to PROJ4

I'm currently working on a better support of LAS 1.4 file format in the rlas R package. In LAS 1.4 format the CRS of the point cloud can be stored as a WKT string. For example this is what I read from ...
2
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2answers
298 views

Seeking for a solution to convert GeoTIFF to 3d WKT

I am trying to convert some DEM in .tif image to polygon geometries representing 3 dimensional triangles that is Well-known text (WKT) - 3D (x, y, z) I was able to use SAGA to convert my GeoTIFF ...
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1answer
102 views

State Plane Scale Factor in WKT

I need to convert an old-style projection file (created with Global Mapper) to a WKT format for use in my GIS program (ArcMap or GDAL or whatever). The problem is that my old-style projection file ...
2
votes
1answer
176 views

What is the history behind WKT and proj.4? [closed]

What is the history behind WKT and proj.4 formats for defining coordinate systems? Does one have advantages over the other? Why do both exist? I'm guessing they were developed independently for ...
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2answers
124 views

Need to zoom into a vector Layer of a multipolygon

I am getting a multipolygon coordinates from DB in WKT format. I am able show the same on the map. But the problem I am facing is while zooming to center of the Multipolygon. Is there any way to zoom ...

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