(1) abstract geometry; (2) storing geographic data in projected coordinates; (3) a generic ESRI term for vector features; a class for "geometry" objects.

learn more… | top users | synonyms

5
votes
2answers
569 views

How to convert geoJSON to python objects?

New to the site, and to geoJSON, and to python. My goal is to read in a file with geoJSON data, and use it to generate shapes to be used in an application that is using python scripting. Python has ...
4
votes
2answers
582 views

How to efficiently determine if a collection of coordinates (polygon) is an ellipse?

I'm attempting to determine a geometry type based on a collection of coordinates and have come across a situation where I'd like to differentiate between what is a "polygon" and what is an "ellipse". ...
6
votes
3answers
1k views

How to fill a hole in a multi-polygon layer on QGIS 2?

I need to fill a hole in a multi-polygon layer on QGIS 2.0. I've set the snapping option for the layer as follows : mode: to vertex and segment tolerance 4 pixels avoid intersection "enabled" ...
6
votes
1answer
185 views

Draw middle ordinate perpendicular to chord, out to curve, with arcpy

I've been assigned to find the radius of road curves. My boss found this article describing a pretty straightforward method of doing so: find the start/end points of the curve; create a chord; ...
2
votes
1answer
39 views

How to generate features to test different implementations of LinearRing?

I have some code that throws the following exception: Points of LinearRing do not form a closed linestring and I want to check if my code is calling this correctly by supplying some features that ...
1
vote
2answers
128 views

Distance between latlongs varies in different projection systems?

I have shapefiles with correct projections. The SRS is EPSG 32735 (WGS 1984 UTM 35S) Now, I have these two coordinates from this projection system: (31.3751,-23.4388) and (31.3779,-23.4355). ...
2
votes
1answer
223 views

Map projection lat, lon to pixel?

I'm trying to find the concave hull of a lat, lon pointset but when I project my points on my map it doesn't look like expected. I've tried a lineare projection and a spherical projection. My data is ...
1
vote
0answers
27 views

PostGIS. Obtain the rotation between two equal Geometries

I've got two features with the same drawing (poliline) but one is rotated relative to the other. I would like no know in PostGIS the rotation between the two geometries to apply this rotation to a ...
1
vote
0answers
121 views

Problem import shapefile in PostGIS database

I am having a Polygon shape-file. When I try to import this shape-file in PostGIS some of the attributes in Geom Field is found empty. But in attribute table when I select that polygon It is visible ...
1
vote
1answer
56 views

ArcObjects- IBorder.GetGeometry() in Python

I am trying to get geometry of frame border trough IFrameElement.Border. I do receive IBorder object, which has .GetGeometry() method. How do I use this method to get geometry of the border? I can ...
2
votes
2answers
141 views

OSM linestring shown as point

I have loaded the following file http://openstreetmapdata.com/data/coastlines to postgreSQL. In visual studio with gdal/ogr and geos enabled: SELECT geom FROM waterpoly WHERE geom IS NOT NULL LIMIT ...
2
votes
1answer
110 views

How to convert a line to points?

I'm working with QGIS and I want to convert a line into many points, does someone know how? Thanks.
0
votes
1answer
86 views

ArcMap toolbox script with draw geometries parameter

I have an arcpy script in toolbox, that need one additional parameter to draw geometry(ies) which will work as a filter. I have done something similar using arcobjects using ...
0
votes
0answers
32 views

ERROR: CASE types geomval and geometry cannot be matched

I am trying to optimise the speed of the intersection query that I am running. However, I am struggling to find the best way to do this. And found a similar bit of sql that looks like it would do ...
0
votes
0answers
72 views

How to find the list of TMC codes by region or by geometry polygon?

Can you please suggest a way to find out all the TMC (Traffic Message Channel) codes by region or by Geometry polygon values. My area of interest : USA
1
vote
1answer
525 views

PostGIS Select Union of Polygons

I have a Postgres 8.4 PostGIS 2.0 enabled database and I've loaded it up with a bunch of shapefiles. I'm trying to get the database to do on-the-fly unions of geometries. Here is the query I'm ...
0
votes
0answers
254 views

Publishing PostGis table using GeoServer REST returns error when geometry column is NOT named “geom”

I tried publishing an existing PostGis table with geometry column named "wkb_geometry" to Geoserver using its REST API. I used the following command: curl -v -u admin:geoserver -X POST -H ...
1
vote
2answers
290 views

Convert 3D WKT to 2D Shapely Geometry

I have the WKT of many linestrings which contains three dimensions, however my script only requires a two dimensional linestring and I therefore want to discard the third dimension. My current code, ...
2
votes
1answer
396 views

How to convert Geometry type column to degree Minutes Second in SQL Server 2008 R2

I have shape column of type geometry and I want to convert X and Y coordinates into Degree Minutes Second format using SQL query and i am using sql server 2008 R2. Currently I got Lat and long using ...
0
votes
1answer
236 views

SQL Data: How to draw circles with a radius based on lat/long data in DB

I have a . sqlite file with many columns, two of those columns being lat and long. I've been searching around for a bit now (don't think I want to be using BuildCircleMbr from spatialite?) but I'm ...
3
votes
2answers
3k views

How to remove duplicate features with the same geometry in ArcMap?

Is it possible to uniquely identify each geometry in a feature layer? Essentially I have a polygon feature layer with many rows of data represented by the same geometry. I would like 1 row for each ...
2
votes
1answer
143 views

Center point approximation of a polygon

I would like to get a center point approximation of a set of polygons so I can do a NN lookup to use for assignment instead of a point in polygon query. Lets say I have this set of polygons: I ...
1
vote
1answer
295 views

SQL 2012 - How can I convert MultiLineString to Geography?

I have a Geometry LineString that I wish to convert to Geography. Since the Geometry isn't valid , When I use MakeValid on it, SQL convert it to MultiLineString and than the Geography creation is ...
0
votes
1answer
198 views

SetGeometry problems when using python/ogr

So i am trying to use the difference function and i pretty much create the new file i want but the Geometry is empty. No error is produced. any help would great! Thanks. #!/usr/bin/env python import ...
0
votes
1answer
383 views

What to do if PostGIS gives error that “geometry requires more points”?

I have a .TAB file. I convert it to ESRI(shp)-->sql and insert it into database. Using PostGIS when I want to convert the data into ESRI file, it shows an error: geometry requires more points ...
0
votes
0answers
139 views

Openlayer seems slow when zooming / panning on vector (geometry line) from geojson. Why?

I have a layer with 7 lines . when I zoom on some of the lines , the maps seems to be very slow. I thought it might be because I bring a lot of points to the client (that represents the line) aa ...
5
votes
1answer
200 views

Can ArcPy 10.1 be used to generate true curve elliptical polygons in a file geodatabase?

As background, this question arose from trying to answer a question on How to generate overlapping polygons from lines output from Table To Ellipse tool? Using the ArcMap GUI it is very easy to ...
2
votes
3answers
306 views

Polyline selection of features with angle turns up to a specified angle

I'm looking for an automated way to select line features that have specified angle between vertexes. That in order to check water mains layer -steel pipes can have only 45 or 90 degrees turns and I ...
2
votes
1answer
99 views

Which fields are standardized to describe a ShapeFiles feature?

I would like to store data into a database which is available here either as JSON or as ShapeFiles. The JSON looks something like this: { "type": "FeatureCollection", "features": [ { ...
0
votes
1answer
907 views

Trying to convert geometry to geography keep failing in MSSQL 2012

In MSSQL I have LineString in Geometry type. When I try to convert it to geography using : ...
2
votes
1answer
77 views

Where would a perfectly vertical vertical tunnel through the earth come out?

I am a programmer. I have a point P1 (lat,lon) given by GPS (WGS84) and I want to know the location of a point P2 if I make a straight line from P1 to the other side of the earth. I have read some ...
2
votes
1answer
239 views

GML - Multi-geometry validation

I'm doing the test to introduce multiple geometry in a WFS service using GML. For now the simple geometry is functional, but I still have some bugs with multiple geometry. I think it may come from my ...
1
vote
1answer
100 views

Insert geometric data to a column from coordinate values in double precision

Screenshot of database http://wp.me/aIW9p-i0 For table “households”, I want to create two new columns: 1) “Geom”, data type – geometry; 2) “WKT”, data type ‐ text; I am intending to do the following ...
2
votes
2answers
196 views

How can I create a multipoint geometry in QGIS?

I've got a Spatialite layer in QGIS with geometry type MULTIPOINT. Now I'd like to add some data in this table in the 'usual' way, so by doing multiple clicks in the map (e.g. left-click, left-click, ...
2
votes
1answer
246 views

Programmatically manipulate GPX data

I need to do the following in Python open OSM & GPX files (I have packages for this) transform points from GPX (like stick a track to roads) calculate the results (distances, cumulative ...
1
vote
2answers
429 views

Why do I get wrong length using STLength on MultiLineString?

I have 2 MultiLineString representing the a route (first is driving there and the second is the return way) . MULTILINESTRING ((34.787315938035292 31.318235314177119, 34.788431415005249 ...
1
vote
0answers
72 views

Why is my linestring not valid ? was recorded from GPX file

I have a linestring that was built from points from GPX file. I've insert it to sql as geometry and when I try to run funcs on it (like STStartPoint ) I get error that line isn't valid and I need to ...
1
vote
2answers
408 views

ST_DWithin uses Geometry or Geography type

assuming I use the following query to match the locations to a poi within 10km distance: SELECT poi.poi_id, h.loc_id, (ST_Distance(poi.geom,h.geom)*111.111) as distanceinkm FROM iut_poi_transl AS ...
2
votes
1answer
279 views

How to perform a cascaded combine from python script in QGIS?

I'm working with a large dataset, and I need to be able to combine up to 400,000 polygons. I have been using the QgsGeometry::combine(QgsGeometry* geometry) function and simply looping over all ...
4
votes
0answers
632 views

Finding the “center of gravity” of multiple points where points have unequal weights [closed]

I'm trying to reduce a set of lat/lons (each with it's own weight) into one lat/lon that is the center of mass of all of the points. however when I map the results the average point falls no where ...
2
votes
2answers
1k views

How do I get that polygon from Javascript ArcGIS API?

I would like to have a user draw a Polygon (or Line) onto a web map with the Javascript ArcGIS API drawing tools. For the life of me I can't figure out how to pull that polygon from the client and get ...
2
votes
2answers
149 views

Is there Shape Metrics Toolbox or equivalent for ArcGIS 10?

I need to compute the geometric properties (e.g. contiguity index, dispersion index etc.) of a series of polygons and I would like to use the Shape Metrics Toolbox. I am using ArcGis 10 and the ...
0
votes
0answers
120 views

several fields and GEOMETRY GetFeatueInfo from Geoserver

Good day!. I have a table in PostGIS 2.0 with several fields of type GEOMETRY. In the geometry_columns they are published in Geoserver 2.2 as layers. This is done as here - geoserver docs, but ...
0
votes
1answer
58 views

How can I transform geometry data to bounds?

My SRID is 3137 and I want to transform geometry data(e.q : "0101000000904160258CC91841C8073D6723545141") to bounds. I need to bounds coordinates for use in maxExtend() function. Help me please!
1
vote
1answer
286 views

Combining polygon geometries with python and QGIS segfaults

I am trying to combine polygons, using Qgis 1.8, and every time I run this script in the python console, I get a segmentation fault. Here is the script: from PyQt4.QtCore import * iface = ...
0
votes
1answer
149 views

QGIS Python - Convert geometry from Postgres to QgsPoint()

I have made a query in Postgres to get some points to use with python. This points are in geometry data. How can I convert that geometry in decimals to use QgsPoint() in python? Thank you
1
vote
1answer
421 views

Intersection with JTS Geometry

I want to calculate an intersection between two geometries with the intersection function from JTS Geometry. What happens, if the geometries have different SRIDs? SimpleFeature sf1=...; //SRID ...
1
vote
0answers
86 views

Python GDAL/OGR: check lines geometries connectivity

I'm working with shapefiles representing roads, so basically it's stored as (poly)lines. I need to perform a road connectivity checking. In other words, I want to ensure that roads meant to ...
2
votes
1answer
353 views

How to get point x and y geometry from a shapefile?

I have a shapefile of US Cities and I want to get the X and Y coordinate of EACH city in that shapefile. I've tried this: for city in city_cursor: geom = city.Shape point = geom.getPart() ...
2
votes
1answer
645 views

How to write point geometries with arcpy instead of gp syntax?

Can someone help me fix some code that simply writes points into a featureclass? It used to work in the older gp. syntax, but I'm having difficulties rewriting it in arcpy for ArcGIS 10.0. In this ...