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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42
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3answers
14k views

Visualising WKT geometry string in QGIS

A very simple question: Is there a simple tool in QGIS to graphically visualise geometry formatted as text? Example geometry: "POLYGON((571178 6337246,571178 6402217,598061 6402217,598061 ...
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6answers
9k views

Converting between Esri Geometry and WKT using ArcObjects?

It seems like there is no means of converting an ArcObjects geometry to the Well-Known Text representation (and vice versa) in ArcGIS ArcObjects API. The only thing I was able to find is conversion to ...
12
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4answers
2k views

Looking for a pythonic way to calculate the length of a WKT linestring

I was quite unsatisfied with Calculating Length of Linestrings in WGS84 in Miles. It kept me wondering if there is a more convenient, Pythonic way to calculate the length of a WKT linestring according ...
12
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3answers
8k views

Are there any online WKT editors?

I've been using QGIS and it's great. However, we can't use that because it has to be installed (please, don't ask). Instead, what we need to do are very simple administrative boundary drawings over a ...
12
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1answer
4k views

Where can I find the WKT standard or reference?

I had a little confusion about the representation of a geometry as well-known-text (WKT). I was searching for the WKT Specs to search for the exact representation, but I did not find the Standard. Is ...
10
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4answers
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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 ...
9
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4answers
6k views

How to convert geometry to WKT using ArcPy?

I would like to be able to convert a single feature (or potentially many features) in an ArcGIS layer into Well Known Text (WKT) format during a geoprocessing operation using Python and ArcPy (no non-...
9
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1answer
417 views

What are the differences between the OGC and ISO WKT/WKB specification?

Are the OGC-Simple feature access and the ISO (ISO/IEC 13249-3:2011 "Information technology - Database languages - SQL multimedia and application packages - Part 3: Spatial") significantly different (...
8
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1answer
10k views

Create a csv with geometry as WKT in QGIS (and choosing the field delimiter)

Is there a way to choose the field delimiter when exporting to CSV with geometry as wkt in QGIS? I have a shapefile with donut holes and I'd like to export it as a CSV. It's for a partner whose DB ...
8
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1answer
2k views

Help with PostGIS polygon geometry - non-closed rings

I've picked up a copy of the super-wicked book 'Python Geospatial Development' by Erik Westra (Amazon link), and I'm working through it. Currently, it's teaching me to load GSHHS coastline data from a ...
7
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3answers
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.NET library to convert KML to WKT?

Anyone know of a free OpenSource .NET library i could use to convert KML to WKT? I know i can use openlayers and there are many JavaScript possibilities, but i need to do this on the back-end.
7
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2answers
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what is the best way to programmatically convert between WKT and Proj4 string?

some shapefiles have a .prj file associated with it. and the .prj file contains the projection info of the shapefile in the format of WKT. Sometimes I need to convert WKT to proj4 string, and ...
7
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2answers
3k views

Converting KML files for use with Python library Shapely

I am trying to get a KML-file (wijken.kml) into Shapely. The KML-file is validated against the proper XML schema, so I guess the input is correct. Routes I have tried: 1) Converting to WKT or WKB ...
6
votes
2answers
5k views

Is there any efficient way to convert Geojson to WKT?

I want to use ST_GeomFromText() to load vector data to PostGIS. However, I don't know how to convert from Geojson type to WKT. N.B. I know I can use OGR2OGR to upload the geojson directly, but I just ...
6
votes
6answers
2k views

WKB to WKT JavaScript function

Turns out json isn't so good at transporting binary data. But with HTML5, XHR2 is now capable of transferring blobs cleanly. I'm looking to transfer binary geometry (to save bandwidth) and decode it ...
6
votes
3answers
2k views

Determine if a polygon intersects itself in OpenLayers

I let the users draw polygons and then I try to save them out to the SQL Server 2008 SQLGeography field, but it is giving me an error: Error 24200: The specified input does not represent a valid ...
6
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1answer
6k views

What's the proper format for WKT linestrings when importing into QGIS?

I'm trying to run the following test CSV through the Delimited Text plugin as WKT data: oid,Line 1,LINESTRING((45.554194 -122.686101, 45.433001 -122.762632)) 2,LINESTRING((45.432505 -122.598327, 45....
6
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1answer
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projection/pyproj puzzle, and understanding SRS format

I have a shapefile that has a .prj file, with the following wkt contents: PROJCS["NAD_1927_StatePlane_New_York_West_FIPS_3103",GEOGCS["GCS_North_American_1927",DATUM["D_North_American_1927",SPHEROID["...
6
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1answer
242 views

What is the definition for a geographic coordinate system with east/west bounds of 0 to 360

I need the coordinate system reference or a projection definition that uses geographic (i.e. lat/lon) coordinates but instead of east/west bounds being defined as 180 to -180, I need them to be ...
5
votes
1answer
552 views

How do you represent text in WKT

I need to label the simple-features/shapes in a Well-known text file. Is there some best practice on how to achieve this? Should I just keep the labels as separate entities linked to the WKT or is it ...
5
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1answer
4k 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. ...
5
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1answer
1k views

Detecting invalid WKT in text column in SQL Server

I've got a whole load of WKT data in a SQL Server table, of which I'm trying to detect the validity. I'm currently doing a query like this: UPDATE f SET f."CurrentGeomValid" = geometry::...
5
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3answers
3k views

How to unproject WKT to WKT in .NET?

I have WKT in this format: GEOMETRYCOLLECTION(POLYGON((491990.250718 6212873.59755,491492.160493 6212904.94117,491265.64715 6212790.54445,491319.517251 6212550.36334,491579.624164 6212637.87553,...
5
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0answers
172 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 ...
5
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0answers
541 views

What traits identify 2D, 2.5D, 3D geometries, and how can you convert downward, such as from 2.5D to 2D? [closed]

In answering OGR - Weird GeomType -2147483645 on polygon shapefile, posed by @Burton449, I came to realize I don't have a definitive grasp on what distinguishes 2D, 2.5D, and 3D geometries. I ...
4
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3answers
241 views

Does a projection's WKT reflect the computer's locale?

This should be quick - we're trying to determine if there are problems parsing some WKT text because the system locale considers the decimal separator to be a comma instead of a period. Anyone know? ...
4
votes
3answers
134 views

How to get WKT for various Spatial Reference Systems?

I need to provide WKTs of spatial reference systems in the APIs provided by GDAL/OGR. Is there some specific place where I can look for WKTs of the spatial reference systems that I'm working with? Or ...
4
votes
5answers
325 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 ...
4
votes
2answers
8k views

How to convert a shapefile to WKT?

I'm trying to convert a shapefile into the simple Well Known Text (WKT) format in the example below (from http://en.wikipedia.org/wiki/Well-known_text). MULTIPOLYGON (((40 40, 20 45, 45 30, 40 40)), (...
4
votes
2answers
999 views

Plotting large numbers of objects on a chart using R and WKT format

I am retrieving thousands of geometry lines in WKT format from a Microsoft SQL Server database. I would like to plot all of those lines in one map, but I am having some difficulty with the code. How ...
4
votes
2answers
692 views

How to generate an image from WKT?

I am looking to programatically generate an image from a WKT string (or any other common format, such as WKB or SQL Spatial geography). Are there any existing libraries that allow for this? I am ...
4
votes
1answer
355 views

Shape looks like big Square in SQL Server 2008

I was provided with a polygon defined in WKT which has 4741 points and am able to insert it as a geography data type within a database in SQL Server 2008. However, when I view it using the spatial ...
4
votes
1answer
505 views

Convert Landmask file into WKT Polygon

I have a land mask file in netCDF (also in ascii, if needed) which basically consists of a lat/long pair and a boolean (1 or 0) determining if that value is over land or not. The thing is, I'm not ...
4
votes
1answer
2k views

Write out a WKT file from a loaded shapefile

We are looking to load and display a shapefile, simple polygons, then write out a WKT string of that shapefile and have the user save it somewhere. Does anyone have some code snippets of that very ...
4
votes
1answer
2k 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?
4
votes
2answers
283 views

can Well Known Text tables be used effectively, stored in Access or Base?

My question is: How do I import WKT text data back into QGIS, and how useful could Base or Access be in storing the data using WKT rather than spatially enabling it within a proper GIS database, like ...
4
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2answers
1k 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 ...
3
votes
4answers
9k views

How to convert WKB to WKT?

how can i convert wkb to wkt form ... i stored coordinates in wkb but now can it will display to use in wkt form
3
votes
4answers
1k views

converting oracle geometry to postgis with 3d data (wkt?)

I am converting Oracle spatial database to postgis. Most of of the spatial data is 2.5d. Meaning we have a Z-coordinate which indicates the depth/height of the element compared to soil level. Getting ...
3
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1answer
305 views

Adding a WKT specified coordinate system to ArcGIS?

I've got a WKT specified coordinate system, how do I add this to ArcGIS?
3
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1answer
254 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 ...
3
votes
3answers
3k views

how to extract lat long from WKT data?

i want to extract lat long form WKT data and stores into arary list i have tried one solution which is proposed by a user but it has some problems String str = tv.getText().toString(); str = ...
3
votes
3answers
87 views

Are nested parenthesis allowed in MultiPoint WKT?

I'm writing a basic parser for common WKT. The Wikipedia entry for Well-known text says that both of these are equivalent. MULTIPOINT (10 40, 40 30, 20 20, 30 10) MULTIPOINT ((10 40), (40 30), (20 ...
3
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3answers
849 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 ...
3
votes
2answers
2k views

How to read csv with WKT geometry in Arcmap?

I have found several parcels I need on a county map viewer. However, the only option to download any of the data is found on a click context menu to "Copy selection as csv" which gives me this: HGID,...
3
votes
1answer
442 views

SQLServer generating invalid WKT

I am a GIS novice using SQL 2008, with C# and the NetTopologySuite WKTReader type to work with some geometries. I have some data which I have been able to save into the database but when I read back ...
3
votes
1answer
46 views

PostGIS: floating point representation problem with ST_AsText

I have a table with geometries, all with about 13 digits of accuracy. While trying to represent them with ST_AsText though, most vertices come out in decimal notation, but some come out in scientific ...
3
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1answer
1k views

Converting wkt to geojson with OpenLayers

I am trying to convert wkt to geojson wiht OpenLayers. I wrote my code based on this question (geojson to wkt). That's what I have so far, but it is not working. Any ideas? var = '...
3
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2answers
815 views

Google Maps Polygon to WKT

I need to convert a Google Maps polygon object (can has multi paths and holes) to wkt string (multipolygon) at client. Then i'll able to save polygon as geography in Sql Server 2012. I tried Wicket (...
3
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3answers
720 views

I have a list of coordinates that make up a route - how can I easily render this shape on a map?

Additional info - I don't need this to be on a map - I just need the shape of the route. Is there anything that can return that shape easily? The list of coordinates are in an xml document and I'd ...