Questions tagged [wkt]

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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91 views

How to use old WKT(version1) coordinate reference system in ArcGIS Desktop?

I have a local coordinate reference system defined with WKT: COMPD_CS[ "test", FITTED_CS[ "", PARAM_MT[ ...
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2answers
784 views

gdalwarp cutline without using a shapefile

I'm currently working with gdalwarp to split some tiffs. gdalwarp -cutline file.shp -dstalpha -of GTiff image.tif split_image.tif I wanted to know if I can use an other source rather than use a ...
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1answer
282 views

st_astext generate an invalid wkt in postgis

The query: select st_astext(dn_geom), st_isvalid(dn_geom), st_area(dn_geom) from t$table Generates an incorrect WKT from a geometry apparently valid: POLYGON((-2.96954161967213 41.4400844183428,-...
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3answers
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Listing coordinates of polygons in WKT format

I have a polygon shapefile made up of 2 shapes (independent of each other). I'm using the code below to print in the ArcMap python console, a list of each shapes coordinates in WKT format. I get an ...
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1answer
216 views

Understand way field (type geometry) in planet_osm_polygon

I'm new to QGIS and I'm using PostGreSQL and QGIS DB Manager to get information from the polygon_osm tables. I'm currently working on the _polygon table and I'd like to get the coordinates for each ...
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1answer
120 views

Convert WKT to Layer arcpy

I have a CSV file with number of records that have WKT Point geometry. I am bit lost on how to insert to this into a new point layer. Sample data from CSV file from GeometryItem Field: POINT (-...
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1answer
473 views

How to generate WKT geometries from true type font glyphs (python)

Does anyone know of a library or tool ( preferrably Python)to convert true type font glyphs into polygonal shapes (for testing GIS algorithms)?
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1answer
821 views

OpenLayers 4.2 - Changing the interaction geometry type from polygon to multipolygon

I would like to make a selection with DragBox interaction and get the geometry type to Multipolygon. Right now I'm getting a Polygon type back : var source = new ol.source.Vector({wrapX: false}); ...
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5answers
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WKT for EPSG:4326 with LON 0 to +360 instead of -180 to +180

I have GRIB2 files that seem to be in a projection similar to EPSG: 4326, except that instead of longitude between -180 and +180 it is between 0 and 360. My intention is to get these files into ...
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2answers
167 views

Creating two-colored map of region in one color, and neighbors in another color? [closed]

As they say, a picture is worth more than a thousand words: Turkey in Wikipedia What I need is to create maps for an educational system, and though we can create them manually in a lot of ...
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2answers
504 views

What CRS to use to georeference map?

I am trying to georeference a raster map from Nepal. What CRS should I use? PROJ.4 or WKT form. I will use the UTM grid to base my reference points on. On the map there is reference to: Scale 1:...
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2answers
179 views

Converting shp file to wkt polygon string using ArcPy?

I used the following code to convert .shp file to .wkt. The code was successful but where can I find the .wkt file (the print row ouput)? Is it possible to add a path for the wkt files to be ...
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0answers
197 views

Passing a WKT Polygon with interior rings to a QgsRubberBand's Geometry with PyQGIS

Starting point is that I select a geometry with the following query in QGIS DB Manager: SELECT 1 AS myid, st_buffer(st_union(wkb_geometry), 5) FROM ax_strassenverkehr WHERE unverschluesselt ILIKE '%...
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1answer
2k views

PostGis vs Oracle Spatial 11g performance

I am having a performance issue updating a table in Oracle Spatial 11G while converting 63,000,000 points to WKT format. I also made a comparison with Postgres. Both Postgres and Oracle run in two ...
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204 views

Seeking example .PRJ file using WKT syntax for Concat_MT?

I've been digging into the WKT format definition found here:WKT Format with the aim of defining a PRJ with two chained affine transforms to go from a known projected system to a local grid. I've been ...
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1answer
404 views

Using WKT (or Proj4) information to define a coordinate system with gdal_translate

The gdal_translate program has an option to define an XML file with the necessary information to download an image using various web map server specifications. I am using this XML option with an ...
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2answers
5k views

How to return WKT of entire polygon with shapely?

Im learning to use shapely and have two shapefiles--forest, and basins. The two shapefiles clearly intersect (basins is completely within forest). But the way I've gone about it only gets the feature ...
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1answer
516 views

ogr ExportToWkt support for m value?

I'm trying to parse a shapefile with ogr and export the values to WKT. The geometries contain a m value but this is not showing in the WKT output. Does ogr support 4D/m values? # My code from osgeo ...
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1answer
313 views

Working with ESRI WKT Spatial Reference in ArcGIS API for JavaScript?

I have been practising ArcGIS in JavaScript (for WMS layers ) and have always faced numerical values of SpatialReference like wkid: 102100, but now I faced in this format: 'PROJCS["...
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1answer
135 views

QGIS: Every input to QuickWKT results in a point at null island

If I open the QuickWKT plugin in QGIS, and choose "POINT (WKT)" from the combo box, and enter the text, POINT (30 10) I get a point at "null island" (0°N, 0°E). The entered WKT appears well-formed ...
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1answer
487 views

Map Info to WKT format

I have files in Map Info format(TAB,DATA,etc) and I want to convert them to WKT(well-known text) format, so that I can store in a DB. do any of you know how to convert Map Info to WKT?
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Generating shapefiles from WKT format polygons using Arcpy? [closed]

I am working with a database containing a geography field representing the Admin1 boundaries of countries. I would like to draw a map of the Admin1 boundaries of Somalia: params = urllib.quote_plus(.....
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517 views

How to convert ESRI .prj WKT string to Proj4 string WITHOUT GDAL

ESRI shapefiles include a .prj file containing CRS information in Well-Known Text (WKT) format. I'm developing a software in which I need to systematically read shapefiles' CRS information, convert it ...
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0answers
134 views

How to define a Topocentric CRS in OGC WKT form?

I'm trying to construct a DerivedCRS in OGC WKT form that describes a 3D local rectangular coordinate system that is sometimes referred to as an LSR or ENU or Topocentric. It has an origin described ...
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2answers
177 views

Odd behaviour with MULTIPOINT layer in QGIS using delimited files and WKT

I'm writing some python to create grid lines, either as a series of densified LINESTRINGs or a set of MULTIPOINTs. The code uses shapely, and I'm writing WKT to a CSV and importing into QGIS(2.18.3) ...
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1answer
74 views

Point to Line for lines and polygons

I have a csv file which I converted to points. It contains features that are a mix of lines and polygons. Format is below. Now I would like to use the point to line processing tool to generate the ...
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2answers
337 views

own style for each WKT

I have this code and it works fine: <script> var raster = new ol.layer.Tile({source: new ol.source.OSM()}); var wkt = 'LINESTRING (30 10, 10 30, 40 40)'; var wkt2 = 'LINESTRING (0 0, 5 5,...
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0answers
371 views

QGIS Formatting LineString [closed]

I'm trying to visualize some directional depth slices and I'm having some trouble getting QGIS to render the lines like I want and it's been driving me crazy. I have a python script that outputs my ...
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2answers
287 views

Python WKT or Proj4 lookup package

I am looking for a Python package that would allow me to input a UTM zone code and output different geo_referencing strings (for example, WKT or Proj4). Are there any lightweight, widely used packages ...
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1answer
782 views

Postgis AddGeometryColumn for WKT with different types i.e. Polygon and Multipolygon

I have some polygon data first;1;MULTIPOLYGON (((30 20, 45 40, 10 40, 30 20)), ((15 5, 40 10, 10 20, 5 10, 15 5))) second;2;POLYGON ((30 10, 40 40, 20 40, 10 20, 30 10)) third;3;POLYGON ((35 10, 45 ...
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3answers
796 views

Getting correct WKT result to 4 decimal places using PostGIS?

I'm using PostGIS version 2.3. I want to get the SW and NE corners of a bounding box, corrected to 4 decimal places. Right now I have this to retrieve the SW and NE corners from my geometry column: ...
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1answer
783 views

Preserving Curve Geometries in Leaflet

Is there any way to represent a polygon geometry that contains a curve accurately in Leaflet (from WKT)? GeoJSON conversion from WKT is insufficient as it digitizes the points of a curve out to an ...
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1answer
824 views

Export geography field from SQL for use in GIS

I currently have a table in SQL server management studio (2012) with a geography column. It definitely has valid spatial data, as I can view it in SSMS: What I want is to export the data as a ...
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1answer
77 views

Error using Postgis 2.3.1

I installed PostgreSQL 9.6, PostGIS 2.3.1 and Pgadmin III on my computer, and I was reading the documentation, so I thought that would be a great idea see the function on practice and then modifie ...
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1answer
106 views

WKT for a doughnut shaped world projection? [closed]

I understand next to nothing when I look at a WKT string, but I've copy-pasted and used a few of them for work. However, I came to think of the doughnut shaped world in which my friends and I play ...
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2answers
882 views

Custom SRS for openlayers 3 (ol3) without an EPSG code

How can openlayers 3 be told to use and work with a custom SRS-definition which has no EPSG-code? May i don't understand it but it seems like ol3 needs an EPSG- or ESRI-code to work. I found some ...
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1answer
508 views

PostGis and datatypes WKT

I dont't have any experience with the geographics databases so I hope that you be patiente with me, the thing is: I know that the datatype geography is used if all you care about is measuring ...
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1answer
1k views

loading a CSV with an embedded GeoJSON polygon geometry in QGIS

This open data portal offers download as CSV file. For larger datasets, that's the only way to download the whole dataset in one go. The CSV format is pretty creative: the polygon geometry is in ...
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1answer
220 views

WKT MultiPoint string not working in GeoServer?

I have a problem with a MULTIPOINT WKT string (SLD file for GeoServer) that is not displaying at all: <WellKnownName>wkt://MULTIPOINT((-1.5 1), (0 1), (1.5 1), (-1 -1), (1 -1))</...
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1answer
443 views

GeoServer: points' symbols with a WKT polygon geometry?

I need to define custom points symbols in a SLD file for GeoServer. It seems that some WKT strings are accepted and others are not. I need to draw a closed line with a fill color. The following ...
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1answer
127 views

Is there a common standard for how GIS information is displayed?

New to GIS programming so this might be a silly question. Is there a standard way to store/transmit how a GIS feature is to be displayed? So I can see there's loads of standard ways of storing tha ...
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1answer
854 views

Convert shapefile to WKT using ArcPy

I am attempting to convert a shapefile to WKT using ArcGIS 10.4. I have seen the question/answer posted here, Converting geometry to WKT using ArcPy?, which is helpful. However, when I follow the code ...
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1answer
1k views

What's this PROJ4 string in WKT?

I have this projection in PROJ4: +proj=tmerc +lat_0=41.836944 +lon_0=-87.684722 +x_0=0 +y_0=0 +datum=NAD83 +units=m +no_defs What's the WKT translation? I saw this site: http://cfconventions.org/...
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0answers
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How to convert Common Alerting Protocol (CAP) <area> to WKT

I've come across some data being sent in the CAP (http://docs.oasis-open.org/emergency/cap/v1.2/CAP-v1.2.html) format, which in turn contains an <area> element with either a polygon or circle ...
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1answer
4k views

QGIS, WKT (Well Known Text) LINES and POLYGON files loaded ok, but POINT not

I have several files in WKT format, and something strange happens when I import them in QGIS (v.2.18.1) (layer->add layer->add delimited Text Layer), files containing lines and polygons are correctly ...
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0answers
41 views

3D wkt geometries - Parse in .Net suggests alternate form

I am having some issues with a built in .net framework class (System.Data.Spatial.DbGeometry in assembly System.Data.Entity). It turns out that this class cannot parse 3D geometries when they are ...
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1answer
350 views

Error when writing SHAPE to WKT with pyqgis and QGIS 2.14

It seems the answer linked here doesn't work in latest version of QGIS 2.14 layer = QgsVectorLayer("/home/reyman/Projets/cours/coursPython/pyQgis/shape/passages/passages.shp", "passages", "ogr") if ...
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1answer
158 views

Python To PostgreSQL - ST_GeometryFromText and NaN

I am trying to import a shapefile into Postgre using python and psycopg2. I have run into a few issues. I am using ST_GeometryFromText() of a WKT string. First, the shape@WKT returns MULTIPOLYGON ...
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1answer
630 views

PostGIS linestring to shapefile error with shapely/fiona

I have a PostGIS layer with linestring and I am trying to write the layer to shapefile using fiona and shapely. Here is what I have so far: from shapely.geometry import mapping,LineString from ...
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0answers
551 views

Convert WKT to EWKB/WKB using GDAL/OGR? [closed]

How do I convert WKT geometry to EWKB/WKB? Here's my WKT: POLYGON ((113.749421064162419 62.38697568386327,113.754636282390067 62.386872575140529,113.755323673085357 62.334314115202005,113....