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.

learn more… | top users | synonyms

-1
votes
1answer
41 views

Adding a column of WKT format in the table (postgreSQL)

I want to include this column of data that are in WKT format (they are mostly straight lines). What data type should I use? I need to create this database for mapping. There are about 30000 features ...
1
vote
0answers
54 views

Differences beetween proj4 string and WKT

What are the differences between proj4 strings and well-known text in terms of the ability to represent a projection, other than for WKT being more human readable?
0
votes
0answers
34 views

Understanding the format: WKB from WKT and how to convert the first into the latter

I don't understand which kind of format I have my data. The column name is wkb_geom, so I supposed that data were in WKB format, but then I was checking around and I couldn't find example of it. Data ...
1
vote
0answers
32 views

ogr2ogr latitute longitude conversion formats

trying to convert shape files into mysql tables. Able to create table and load data successfully using OGR2OGR. Only challenge I see is latitude/longitude is not exactly the same format as one of my ...
1
vote
1answer
146 views

Using WKT.writeGeometry for 'Circle' Geometry in OpenLayers?

In my application which I'm building using OpenLayers3, I'm trying to extract the geometry of a feature to WKT using var format = new ol.format.WKT(); console.log(format.writeGeometry(geometry)); by ...
0
votes
1answer
40 views

Problem with importing WKT to PostGIS

I'm trying to import WKT (http://polygons.openstreetmap.fr/get_wkt.py?id=2413177&params=0 - boundary of one of districts of Łódź) into PostGIS database and convert it to geometry. I've created ...
0
votes
1answer
50 views

How can I get public transport maps in WKT format?

I can get street maps from openstreetmaps.org (XML) and convert it into WKT with the tool osm2wkt. There are several people creating specialist public transport maps: The Transport Map layer on ...
0
votes
1answer
62 views

Parsing XML file with hundred polygons using OpenLayers

I'm using this script but It's not working. <script type="text/javascript"> var raster = new ol.layer.Tile({ source: new ol.source.OSM() }); var xml = new OpenLayers.Format.XML(), wkt = new ...
1
vote
0answers
33 views

PyQGIS - Syntax for importing WKT file

I couldn't find any proper example of how to import a .csv with WKT coordinates (Polygon) in PyQGIS. Here are more details on my .csv. I am working with polygons. The delimiter is a semi colum, and ...
0
votes
4answers
164 views

Fix Self Intersecting Polygons Manually

I are looking to implement a method to fix self-intersecting polygons by editing the vertex order. We want to take the polygon rings and re-arrange/add in vertices to make a valid polygon. This is ...
0
votes
0answers
47 views

How to add new SRS/Projection/WKT to the GDAL database

I'm using GeoServer, OpenLayers(3.0) and the GDAL utilities. GeoServer has one (or more) SRS/Projections that is/are NOT present in the GDAL database of SRS/Projections. I can get the well-known ...
3
votes
1answer
68 views

Why does projection WKT differ between osr.SpatialReference and gdalinfo

I am writing a simple geotiff using the GDAL python bindings, but the projection WKT reported by gdalinfo differs from the source. The script from osgeo import gdal, osr import numpy # Create ...
1
vote
1answer
75 views

Parsing large GeoJson geometry to WKT

I'm reading a very large json file as an InputStream in Android with JsonReader. This json has a geometry object like so.. "geometry":{ "type":"MultiPolygon", "coordinates":[ ...
0
votes
1answer
38 views

How can I convert bytes to geometry?

Recently I have reviewed that postgreSQL provides support for Geometry objects in database. But in my old sql servers I have bytes data type for shape in database. Now I want to convert those bytes ...
0
votes
0answers
41 views

GeoServer GeoJson with coodinates in WKB?

I'm using a GeoJson query to GeoServer to update data in existing sqlite database used in an android app. The geometry column in that database is in WKB format, because like this the database is ...
0
votes
0answers
36 views

NDVI Web services over Victoria australia

Does anyone know of any web services that are available where you can pass...say a WKT polygon or point and return the mean NDVI or NDVI from that point from an array of the most recent NDVI runs?
0
votes
0answers
54 views

OSGEO/GDAL and Rotated Pole Grids

I have a netCDF containing a raster in a rotated pole grid. I have a script for converting the desired information to GeoTiff, however it requires projection information in the form of WKT string. ...
1
vote
0answers
36 views

Max length for WKT name

First of all, sorry if this is obvious or stupid questions. I am not very familiar with geographic information system. My question is, is there max length limitation on WKT name? see the bold text ...
1
vote
2answers
185 views

How are ESRI WKT projections different from OGC WKT projections?

Does anyone know the precise list of differences between esri wkt and ogc wkt projection format strings? I know there are various tools to help convert from esri wkt to ogc wkt, incl gdal utilities ...
0
votes
0answers
61 views

strange result of spatial functions postgis

I have a problem with different result of spatial functions for same geometry. For some reason result I get when I use geometry from database is different then result when I load same geometry from ...
1
vote
0answers
49 views

How to change Axis Order when transfering data from WFS to Postgis DB

I am using GeoKettle to transfer data from a WFS service to a Postgis DB. The projection of the geometries is WGS 84 : GEOGCS["WGS 84", DATUM["World Geodetic System 1984", SPHEROID["WGS 84", ...
3
votes
2answers
308 views

What is the best way to get from wkt to shapefile in Python?

I am querying tables from a SQL-Server database and would like to convert the table into a shapefile. It has wkt geometries and wkb as columns in the table, along with other attributes that need to ...
4
votes
4answers
143 views

How do you generate WKT from a graphic drawn on a map?

All, In order to do some quick analysis using SQL spatial, I'd like to generate spatial objects using the STGeomFromText / ST_GeomFromText function. With point data, I can do this by geocoding an ...
2
votes
1answer
146 views

Ideal file format for QGIS that allows mixed geometry types?

I have a spreadsheet for an archaeological project that is hosted on Google docs. This allows multiple contributors to edit and update the table as revisions and field data comes in. The table is not ...
0
votes
1answer
186 views

How to transfer a WKT string from OpenLayers to Geoserver or PostGIS?

Supposing I have created a Vector Layer in OpenLayers and then transformed it to WKT or GeoJson, how can I export it from OpenLayers, and possible import it to PostGIS or GeoServer?
4
votes
2answers
2k views

Online WKT and GeoJSON viewer

I once found a great but simple webpage that has a drop down with several text-based GIS formats such as GeoJSON and WKT, and a text box to copy/paste your data. The feature is then drawn on a world ...
0
votes
0answers
87 views

R PostGIS convert SpatialPolygon to PostGIS table

I've been having some success in scraping some webdata and converting it from HTML to spatial data as originally asked here: Parse PHP/HTML to shapefile or similar I've been using R to both fetch the ...
1
vote
1answer
126 views

Java library for reading geojson from MySQL

I am looking for a way to retrieve mysql geometry data as geojson from the database either using a java library or for converting wkt to geojson using either java or javascript. Currently I am doing ...
0
votes
1answer
21 views

Is OpenLayers compatible with OGC WKT SRS definitions?

I'm trying to use WKT in OpenLayers. Proj4js seems to have no problem with this but the OGC definition describes the units as "US survey foot" whereas OpenLayers has an INCHES_PER_UNIT definition of ...
0
votes
0answers
124 views

Convert series of WKT to Shapefile

I have seen am ability in SQL Server 2008 Spatial Tools here that saves result of query as shapefile..I am intrested in how to do this task using C#..Is there any way to do this?I found ways to ...
1
vote
1answer
295 views

Convert WKT (or geojson) geometry to numpy array of coordinates

I am looking for the fastest way to convert WKT or geojson geometry from string to numpy array of coordinates. Is it possible to do it strictly in Python and without creating geometry object such ...
1
vote
1answer
98 views

WKT: What is the reasoning behind the concept of a POINT EMPTY?

In data formats like WKT and WKB, we have ways of representing "empty" geometries. That all pretty much makes sense: a "LINESTRING EMPTY" is a LINESTRING type with 0 vertices. Same with a MULTIPOINT, ...
3
votes
1answer
178 views

extract vertices from dbgeometry value

Who knows the elegant way to extract coordinates of polygon vertices from well known text representation of DbGeometry value? Here's my polygon for example: {POLYGON ((52.808019 -1.345367, ...
1
vote
0answers
60 views

from shape files to a database [closed]

I've previously converted simple shape files to WKT so that I can store them in RDMS that has spatial capabilities. I'm a new user to QGIS, which I'm using to browse a shape file. But now I have a ...
0
votes
1answer
29 views

Failing to get wkt to reference for a multiline

I apologize, I'm quite new to WKT (and most everything else). I have a shape that I've exported to csv. & geoJson to be loaded into CartoDB. Unfortunately, the geoJson doesn't work so I am trying ...
1
vote
1answer
513 views

How can I convert WKT to SHP?

Using ArcGIS, ArcInfo and fme, I would like to transform data which contains wkt geometries (points, lines and polygons) into SHP. Has anyone a workflow for doing such a transformation?
5
votes
0answers
73 views

Is there a limit to the number of polygon points you can export to CSV in QGIS 2.4?

Using QGIS 2.4 I am currently importing a csv file with ~30,000 polygons (polygons in WKT format). I also have a United States shapefile. I have used the Clip function to get only the polygons that ...
1
vote
1answer
322 views

How to create WKT file readable by QGIS 2.4.0

I am trying to create a well-known text (wkt) file that can be imported into QGIS ver. 2.4.0 Here's a minimal working example of the geometry I wish to represent. POLYGON((-125 52, -125 21, -98 21, ...
2
votes
1answer
177 views

Transform wkb to gml geometry using FME

Maybe (and probably) this is stupid question, but I am totaly new to FME and geometry conversion. I need to transform WKB field from SQLServer to GML geometry using FME software. How can I do this?
2
votes
0answers
30 views

EPSG codes and water level datums

I'm curious if, and how, people use EPSG defined water level vertical datums such as Mean Low Water. There is specific guidance to not use the OGP EPSG definition: Remarks: Users are advised to ...
0
votes
1answer
417 views

Reproject WKT Polygon with Javascript

I have a polygon in WKT in EPSG:4326: polygonWKT = 'POLYGON((13.215179443359373 52.588032137196755,13.42803955078125 52.592620721000365,13.454132080078125 52.46897854656702,13.347015380859375 ...
1
vote
3answers
504 views

geography, geometry, distance, and wkt - PostGIS

I'm trying to understand the data conversions that happen in PostGIS when calculating distances in SRID 4326. Why is it that when I run on my marin_jobs points table: select cast (the_geom as ...
0
votes
2answers
620 views

Returning string from OpenLayers.Format.WKT write? [closed]

How to return a string from OpenLayers.Format.WKT write this.innerHTML = new OpenLayers.Format.WKT().write( layer.selectedFeatures[0] ); my full code is like this please suggest me... ...
1
vote
1answer
186 views

Shapely WKT precision/rounding

I'm using Shapely's wkt.dumps function to get WKT from geometry objects. I can't seem to find a way to limit the precision of the coordinates. Any help is appreciated.
0
votes
1answer
94 views

Using Well-Known Text and geocoding on Load

So, I have tested adding columns with the WKT format into Carto, and it has always worked great (I tried 1 row, then 1000 random rows from our data). I geocoded it on load by naming the column with ...
3
votes
1answer
2k views

Parameter values to create a vector grid with 1km x 1km cells?

I created a shapefile from WKT in QGIS using the values from this link. I want to create a vector grid with 1kmx1km cells but I can't figure out what values need to be set for the X and Y parameters. ...
1
vote
2answers
434 views

Does OpenLayers3 support WKT format?

How can i show spatial data(Point, LineString,Polygon) on bing map using openlayer3?
0
votes
1answer
91 views

How to convert this geometry location format to a qgis usable format?

I am a beginner with regard to dealing with gis information, so please bear with me. I would be obliged if someone could help. I have data on asssembly constituencies of Delhi, with these ...
3
votes
1answer
887 views

Well-known text (wkt) validator

Is there anything like http://jsonlint.com or http://geojsonlint.com for WKT? How can I validate a complex WKT string, say e.g. a Multipolygon?
2
votes
0answers
108 views

Working with WKT data in XML File in SQL Server

Anyone have experience with importing XML files into SQL server 2008 or 2012 that have a WKT element that includes the geometry for each feature? I can get this to easily work using FME software but ...