(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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3
votes
1answer
532 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 ...
3
votes
2answers
858 views

Visualize Spatial Data in Reporting Service

Is it possible to visualize a piece of geographical map from SQL server Spatial data (geometry, not geography) in a report from reporting service? If yes, how should it be done in a course of action. ...
3
votes
1answer
1k views

geometryType property of Vector Layers in OpenLayers

ORIGINAL: I have a couple questions that are focused around the geometryType property with vector layers. When you create a vector layer you can set the geometryType property to limit the geometry ...
3
votes
1answer
609 views

Is it possible to figure out which “Path”(PointCollection) is clicked on within a PolyLine?

I am using ArcGIS WPF's Polyline to plot several lines (PointCollections). Adding a Path(PointCollection) looks something like this. PointCollection collection = new PointCollection(); PolyLine ...
3
votes
3answers
248 views

How to display a table with more than one geometry column in QGIS?

In PostGIS, it is possible to use addgeometrycolumn more than once on the same table. Example: I have one table "scenes" with many attributes, and 2 geometry columns: the_geom1 and the_geom2. select ...
3
votes
1answer
455 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 ...
3
votes
2answers
151 views

How do you determine how straight a LineString is? [duplicate]

I have a bunch of LINESTRINGs and need to classify them based on how strait they are. My idea is to compare the length of the LINESTRING to the distance between the first and last POINTs. I'm ...
3
votes
1answer
217 views

How can i topologically sort 2D triangles and put in an array?

I have a set of 2D triangles in a Geometry array which together forms a connected strip when placed them according to edge adjacency. However, in the array they are not in topological order based on ...
3
votes
2answers
225 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 ...
3
votes
1answer
455 views

Limit Zooming Geometry Features in OpenLayers

I draw flag feature on my map as follows: myVectorLayer = new OpenLayers.Layer.Vector("Flag Geometry", { renderers: renderer, isBaseLayer: true, projection: new OpenLayers.Projection("EPSG:900913"), ...
3
votes
1answer
347 views

Is ST_GeomFromText better than providing direct geometry?

I have been working with postgis recently,and in my query if I use ST_GeomFromText it execute faster than running a sub-query to get geom. I thought ST_GeomFromText will be more expensive but after ...
3
votes
1answer
1k 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. ...
3
votes
1answer
455 views

Open dataset(s) with centroids or other geometry for WOEIDs?

The Yahoo! GeoPlanet data is available for download but this data only includes the object hierarchies without any associated geometry. Do anyone know if there is an open source for geometry ...
3
votes
1answer
25 views

Change feature class from ESRI native geometry to SQL Server geography

Original question: I have found a lot of documentation on importing and using query layers from SQL Server into ArcCatalog/ArcMap/etc. However, when you change the projection of a feature class or use ...
3
votes
0answers
43 views

Interpolating point to nearest polygons to compute street width in posgis

I am trying to calculate the width of streets (line.shp) in postgis using reference point (ref_point.shp) (yellow point features) and building polygons (building.shp). The red point features are the ...
3
votes
0answers
76 views

How do I handle heading in UTM coordinates?

In a nutshell: Given a standard (angular) GPS measurement and heading, relative geographic north. If i take my GPS coordinates and turn them into UTM coordinates, do I also have to convert my heading? ...
3
votes
0answers
518 views

C# implementation of concave hull / alpha shapes

I'm looking for a C# implementation of the Concave hull (alpha shapes) algorithm. I already found several Java, Python and C++ implementation but no C# version. The other implementation are quite ...
3
votes
0answers
164 views

What is the area that OGR extracts from the (geometry) shp files for polygons?

The ESRI July 1998 technical documentation for polygon shapefiles at page 10 makes no mention of either area measures or length measures (apart from byte/record-layout matters). Yet OGR enables me to ...
3
votes
1answer
557 views

OpenLayers: How to get *real* centroid of a Line Geometry/Feature?

I have declared a line geometry as: var lineString = new OpenLayers.Geometry.LineString([source,target]); then I am trying to get the centroid of this lineString as lineString.getCentroid(). But ...
3
votes
2answers
148 views

Find gap in / endpoints of linestring

I have a set of features of type linestring. I'm trying to polygonise the linestrings and assumed that they were closed (naive me :) ). Of course some were not closed and I'm trying to locate the gaps ...
3
votes
2answers
1k views

How to densify a polyline according to a specific length? [duplicate]

Possible Duplicate: Add vertices to lines I am using QGIS 1.8.0 I would like to densify a polyline according to a particular length of segment (ex. 200 m). I know it is possible with other ...
2
votes
4answers
289 views

Transform GeoJSON geometry to WKB

I need transform geometry from JSON like: ...
2
votes
2answers
955 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 ...
2
votes
1answer
324 views

Use arcpy to check whether feature class geometry has ZM

I am looking for a programmatic way using arcpy to determine whether or not a feature class (FC) has Z and/or M geometry. It's easy enough to get the geometry type using the code below, but this just ...
2
votes
2answers
1k views

How to split circles in 8 quadrants

I am using ArcGis 9.3 and I need to split a large number of circles in quadrants. The circles corresponde to a 200m buffer of a point layer and, for each point, I need to split the buffer in 8 ...
2
votes
2answers
858 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
2k 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 ...
2
votes
2answers
397 views

Several questions about using spatial data?

If you have spatial data for SQL server, can you use the spatial data (both geometry and geography) in another application for instance ESRI ArcGIS? Is spatial data a standard that every GIS ...
2
votes
1answer
2k views

How to get the radius of a “circle” in Openlayers

How do you get the radius of a circle in openlayers? I have searched quite a bit and cannot find any resource for this. please help. Here is my code but I want the radius or circumference of the ...
2
votes
1answer
766 views

arcpy Geometry tools give incorrect results?

I'm new to python and arcpy but I've been trying to learn how to run geoprocessing tools using arcpy. I have (for this example) 2 shapefiles, a and b, which are both polygons. From plotting them in ...
2
votes
1answer
115 views

Outward buffering

I get the ConvexHull of a set of polygons using ST_UNION and ST_CONVEXHULL functions using PostGIS. I want to know how to create an outward buffer of the created convexhull in PostGIS?
2
votes
1answer
89 views

Can a PostGIS table or view have two geometry columns?

I am just wondering if it is possible for PostGIS to have two geometry columns. I use shapefile a lot, which has only one "Shape" column for geometry and all geometries in that column has the same ...
2
votes
2answers
189 views

How to find multiple centers of gravity?

Say I have a number of customers in a geographical area, marked "c": Each customer has a Lat/Long. I would like to find x number of points, in the same space, that best serve the customers, ie. ...
2
votes
3answers
98 views

ogr: what is the advantage of using `geom.Clone()` over `geom`?

What is the advantage of using geom.Clone() over geom? Simple example: geom = link_feat.GetGeometryRef() newfeature.SetGeometry(geom.Clone()) # or newfeature.SetGeometry(geom) ...
2
votes
2answers
290 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
3answers
669 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
856 views

Can you explain this WKT multipolygon format?

I am confused by the output I'm getting from ogr2ogr when converting a shapefile to WKT. What I'm expecting to see is something in the form below (from Wikipedia): MULTIPOLYGON (((40 40, 20 45, 45 ...
2
votes
3answers
1k views

How to create Esri Flex Geometry from WKT

I am working with Esri flex 2.3 API, I am also using Abode BlazeDS for server side binding. I am sending a geometry as WKT from server into my flex client and I am looking for a way to convert the ...
2
votes
2answers
71 views

Copy geometry from one layer onto attributes of another?

I have two polygon layers, A and B, that have the same features but totally different attributes. I want to use the attributes from layer A, but I want them to have the more accurate geometry from ...
2
votes
2answers
62 views

Feature Geometry/shape changed event in arcObjects

I have a feature class(polyline). there are 5 features in the feature class. I want to get notification when user changed property any of feature of feature class. How it can be achieved ? I am using ...
2
votes
2answers
92 views

Query Features in Certain Direction

I have a polyline that I would like to query features that are on it's left, right, top, bottom. I am not looking for the features surrounding it but for features that are on a certain location from ...
2
votes
1answer
198 views

QGIS crash when I try print geometry

I do (it works): from osgeo import ogr inputds = ogr.Open(r'c:\temp.shp') inputlyr = inputds.GetLayer() for i,feature in enumerate(inputlyr): print i, feature.GetGeometryRef() Output: 0 ...
2
votes
1answer
273 views

When would a PostGIS geometry compare using ~= return true when ST_Equals returns false?

I have a couple of featureclasses in a 10.2 geodatabase/PostgreSQL 9.2.2 database and I've been struggling with the FeatureCompare tool--it is telling me geometries are different on some features ...
2
votes
1answer
5k 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
1k 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 ...
2
votes
3answers
3k views

Convert coordinates to geometry (polygon) using QGIS

I have an Excel sheet with grid data including geographical coordinates. I know that the coordinates represent areas, i.e., a multi(polygon). However, the data lacks geometry information. I'm looking ...
2
votes
2answers
107 views

How to create a PostGIS table with arc support compatible with QGIS?

In postgis database I have two tables - let's say 'polygons' (gid, the_geom,MultiPolygon,srid=2180) and 'lines' (gid, the_geom,MultLineString,srid=2180). I'd like to use "Add circular string tool" ...
2
votes
1answer
96 views

Create geometry from a result of intersection [closed]

Split a polygon in half with an extended line public Ipolygon CreatePolyFromIntersection(Ipolgon polygonA, Ipolygon bounradyThatcontainsPolylgonA, IFeature lmark){ ...
2
votes
1answer
98 views

Testing if Geometry is convex using JTS?

I'm using the Java Topology Suite and I'd like to efficiently check if a Geometry (a Polygon in fact) is convex or not. I currently do if (geometry.convexHull().equals(geometry)) but obivously that ...
2
votes
1answer
79 views

Geometry in QGIS 2.6

This might be a beginners question, but I could not find an answer on the internet. I drew a couple of polygons in a vector layer and I am trying to get some basic geometric information into my ...