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

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2
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1answer
239 views

LinearRing getVertices implementation

I'm fairly new to OpenLayers so please excuse me if this is an ignorant question. I'm curious why the LinearRing getVertices implementation getVertices: function(nodes) { return (nodes === true) ...
2
votes
1answer
463 views

polygon map overlay algorithm

There are many algorithms for binary map overlay operation in vector data format which take two layers of map and produce resultant layer i.e overlaid layer as output. I am wondering whether there are ...
2
votes
2answers
133 views

MMP of geometries

MBR is used for extent of geometries.. then what is the use of MMP.. is it for visualization the objects?
2
votes
1answer
61 views

QGIS Python - raster as point layer, coordinates issues

I would like to create point layer for storing values retrieved from a raster file. My idea was to iterate through all raster cells. If cell value is different than NULL, I wish to create a new point ...
2
votes
1answer
46 views

Difference between: join, merge and group

Suppose it is desired to make polygons A and B, and their respective attributes to be one unique polygon C. What is this GIS operation called? Is there any difference in GIS terminology about ...
2
votes
1answer
56 views

Python library for geometrical calculations using with GRASS GIS?

I have to do some geometrical calculations in 2D(point, lines, line segments and intersection points) in Python, and then use it in GRASS GIS. What is the best library to use for it? I'm trying with ...
2
votes
1answer
366 views

How to perform SQL query using .STContains in MS SQL Server

I have a table that stores polygons and a table that stores points with a value field. Both sets of data are stored using the Geometry type in MS SQL Server. I have a simple requirement - I need to ...
2
votes
1answer
33 views

finding the nearest point outside a series of geometries

I have db with a very large amount of geometries (circles), most of them overlapping. I'm trying to come up with a way to find the nearest point (from your current location) that is not within any of ...
2
votes
1answer
147 views

How to get the width and height of a rectangular polygon in PostGIS

I have a table with point features saved in the my PostgreSQL database, and I can run the following query to get the extent of the point features and I turned the extent back into a geometry: SELECT ...
2
votes
1answer
123 views

Getting geometry of drawing in ArcGIS Server JavaScript API

To me, ArcGIS Help and Online Resources is always full of unneccessay information and missing some important points. For example there are lots of samples for drawing but I couldn't find any thing for ...
2
votes
1answer
205 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 ...
2
votes
1answer
469 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 = ...
2
votes
1answer
263 views

How to modify the coordinates of a SHP geometry using Geotools?

I have a shapefile with some polygons. I would like to change the height for this elements using Java. The rest of the attributes should be the same. I've thought using GeoTools but I haven't found ...
2
votes
1answer
112 views

Which is better for storage? Geometry column or varchar?

Objective: Need to store and retrieve a list of geometries from the database. Basically these are drawn by the user using OpenLayers which I would like to save and present again as a list (kind of ...
2
votes
1answer
472 views

Geometry valid in PostGIS turns out to be not valid in Oracle

Geometry is in PostgreSQL database. It is valid. Geometry is exported as GML and then inserted into Oracle database. Then function SDO_UTIL.RECTIFY_GEOMETRY(geometry, tolerance) is called, which ...
2
votes
2answers
2k views

Downloading Google Maps municipal geometry

When searching for a city on google maps, google is that smart it displays a geometry line on the boundary off the municipal. See this link: http://g.co/maps/23dz5 Is there a place in the google maps ...
2
votes
1answer
1k views

How to make a predetermined Polygon (Circle) From 4 Coordinates, The Radius and Center Longitude and Latitude in Openlayers

I know how to make a predetermined Polygon in Openlayers (see below). Please have a look at http://studio.netnrg.co.za/dev/rnd/blake.loizides/openlayers var feature2 = new ...
2
votes
3answers
747 views

How do i find out geometries for areas?

I was wondering if anyone could help me out with a website which I can use to get geometries for a area. What I'm looking for is something like google maps where I can drag a cursor over a area of the ...
2
votes
1answer
23 views

TSQL Geometry Query Requires conversion to string

If I specifically define some polygons and check for containment, I get a correct result: DECLARE @g geometry; DECLARE @g2 geometry; SET @g = geometry::STGeomFromText('POLYGON((407305 100826.5, ...
2
votes
2answers
91 views

How to handle coordinates accuracy in ArcGIS

I am creating very basic rectangular polygon using very basic a Python code nCols,nRows=100,100 corners =[[0,0],[0,nRows],[nCols,nRows],[nCols,0],[0,0]] ...
2
votes
1answer
78 views

Add XY Column in QGIS [duplicate]

Following on from a previous question of mine, where I was given coords in degree-mins, I have successfully converted them to decimal degrees, thanks for the help. I have created a CSV file from ...
2
votes
1answer
261 views

QGIS 2.2 rendering problems

i have a problem with some geometry. When i run the check geometry validity i get an error coming back that the rings are not closed, so recangular forms that i have surveyed are showing up as ...
2
votes
3answers
363 views

Fastest way to join points table to polygons tables in ORACLE

I have two tables in 11g oracle db, one with points geometry, one with polygons. Currently I need to enrich the points table daily with the name of the polygon (country) that the point is inside, but ...
2
votes
2answers
194 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
1k 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 ...
2
votes
1answer
365 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 ...
2
votes
2answers
210 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 ...
2
votes
1answer
595 views

How to split zAware polyline by points programmatically with C#?

I'm trying to split a polyline by the boundaries of a polygon using IPolyCurve2.SplitAtPoints using C#. The polyline I'm trying to split is zAware and holds elevation values at a regular interval. ...
2
votes
2answers
178 views

Programmatically change geometry column in OpenLayers WFS layer

is there a way to programmatically change the geometry column on which a WFS layer is based and displayed? WFS (from GeoServer) is correctly returning me two geometry columns, I want to change "on ...
2
votes
1answer
433 views

Remove stale/obsolete geometry columns from the geometry_columns table

I understand that the function Populate_Geometry_Columns() inserts records in the geometry_columns table for geometry columns that are not yet listed there. However, an invocation of ...
2
votes
2answers
691 views

Updating polygon geometry: deleting inner rings with python

I've searched, but can't find clear explanations how can I simply delete inner rings from existing polygons with python or extract outter rings and overwrite the geometry. Seems GDAL/OGR should be the ...
2
votes
1answer
524 views

The minimum bounding circle of geometry that crosses the 180th meridian

Background: I've been given a task where I have to calculate the minimum bounding circle of Alaska (for the purpose of running a Roeck test). I'm using the Census' state level geometries available ...
2
votes
0answers
36 views

Reverse parameters of a projection map

I'm user of a soaring simulator named "Condor Soaring". This simulator is at the center of a community of enthusiastic people who build sceneries (landscapes) which represents quite accurately real ...
2
votes
0answers
105 views

QGIS : cannot change the z-coordinate of a point shapefile using the wkb geometry format

I am using QGIS Desktop 2.5.0-Master with GDAL/OGR 1.11.0 on a windows 7. I am working on a little pyQGis script that should modify the z-coordinate of points in a vector shapefile based on a value ...
2
votes
1answer
82 views

Is a point within a polygon

I need help in this question. To explain briefly -- the question is: Whether a point with coordinates lng:-80.087535 lat: 42.054246 lies over or under line with coordinates: lng: -80.267831 ... ...
2
votes
0answers
78 views

Is there a way to eliminate duplicate 'point clusters' in SQL Server 2008 r2 spatial?

I am using the ST.Distance function to identify clusters of geometry data points. Each point has a unique reference number associated with it. I would like to eliminate duplicate clusters from the ...
2
votes
1answer
166 views

How do I use code (preferably c#) to clip all points within a shapefile that are not contained within a polygon?

So the task is simple: I want to take a point shapefile as input and remove all of the points that are not contained within a polygon. I'm using DotSpatial to do this, but the catch is that there are ...
2
votes
0answers
64 views

PostGIS does not export shortest path to Shapefile

I am trying to draw a bunch of lines overlaying the globe map in a WGS84 projection. To this effect I have created a PostGIS DB with a table that has one column containing linestring data. My problem ...
2
votes
1answer
44 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 ...
2
votes
1answer
186 views

Calculating area [closed]

I have a polygon layer. I toggled to edit mode. I added a new column, while number (integer) and called it "area". I then use the field calculator - geometry - $area to populate the polygon area for ...
2
votes
0answers
71 views

Critera for geometry or geography

What criteria do you need to take account to before you choose geometry or geography map? Is there a book or page about it?
2
votes
0answers
180 views

how to convert lat and longitude into distance near poles?

I am trying to convert latitude and longitude into meters in polar regions. I am looking for higher accuracy upto 0.00 meters preferably. I tried the haversine formula but it doesnt seem to be ...
2
votes
1answer
772 views

Using MS SQL 2005 as the data store in GeoServer

In my project, I am trying to set up a simple WFS service in GeoServer in order to create a layer consisting of point features. I have succeeded doing so with the points being stored in a shapefile. ...
1
vote
2answers
3k views

How to initialize a WFS Layer?

Here is the code block (the layers are stored in Oracle database): var saveStrategy = new OpenLayers.Strategy.Save(); var adresspt_wfs = new OpenLayers.Layer.Vector("Address points WFS", ...
1
vote
2answers
163 views

Ensuring SRID on geometry column in PostGIS

I am using a table that has a geometry type column called "wkt". Its definition in the table looks like this: create table sometable ( ... wkt geometry not null, ... ); I want to change it ...
1
vote
2answers
167 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). ...
1
vote
1answer
1k views

Input of in-memory geometry object to Dissolve tool in ArcPy script throws Error 000732?

In an arcpy script, I run a Union on a list of geometry objects. The output is set to an empty geometry object. The Union runs fine. What I am trying to do is then feed that output into the ...
1
vote
1answer
931 views

PostGIS and geometry column

I have a csv table. Each record includes a start node (lat1,lon1) and an end node (lat2,lon2). I have already imported the .csv into Postgresql 8.4. Now I would like set the geometry column. I tried ...
1
vote
2answers
2k views

what is the format of Geometry data type of SQLServer 2008

I want to know, In which format the Geographic data stored in geometry data type of SQLServer 2008.it looks like a long string,like 0xE6100010466DFEOA4089663524....... for one polygon. My second ...
1
vote
2answers
124 views

Order sql server spatial geometry distance by the nearest

I have a geometry column in a table, I want to get the N nearest neighbours; here is a specific example with the geography type DECLARE @PTO Geography = Geography::STPointFromText('POINT(-57.432546 ...