(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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5
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223 views

Why do file geodatabase and SDE readers produce different fme_geometry types?

I have one very simple workbench that I am running against both SDE (9.3) and FGDB (10.0) sources. I noticed two different fme_geometry values for same type of objects. For the first one, i.e SDE ...
4
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0answers
334 views

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

In answering this question, posed by @Burton449, I came to realize I don't have a definitive grasp on what distinguishes 2D, 2.5D, and 3D geometries. I certainly realize Z/elevation values are ...
4
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0answers
786 views

OpenLayers: WFS request to GeoServer to retrieve “name” & “featureNS”

Using WFSGetCapabilities I sent a GetCapabilities request to GeoServer. From the result of WFSGetCapabilities().read(), I can loop each featureType and retrieve some basic info(e.g., name, title, ...
3
votes
0answers
31 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
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0answers
78 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 ...
2
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0answers
44 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
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0answers
151 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
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0answers
101 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
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0answers
66 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
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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
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188 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
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0answers
351 views

ArcGIS/arcpy: Geometry object comparison methods not working. Do they take z values into account?

I have an arcpy script that makes calculations based on an input PolygonZ feature class. What I need to do in several places in the script is test whether a point falls within a polygon in 2D. In ...
1
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0answers
58 views

How to determine ring orientation from lat/long coordinate points?

We have some set of point coordinates in lat/long which contribute to a polygon. From this set how do we determine the polygon is clockwise or anticlockwise?
1
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0answers
37 views

Zonal geometry output in ArcGIS

Is there a way to specify the coordinate type in Zonal geometry output in ArcGIS? I am trying to perform zonal geometry on a raster and in the resulting output, the XCENTROID and YCENTROID are in ...
1
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0answers
82 views

Inflating the boundaries created with convex hull

I have a set of lan and lat points and have plotterd a convex hull for them using QGIS. A polygon is created along the set of points and plotting them on the MAP. Now I am trying to inflate the size ...
1
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0answers
32 views

Needing to find parent zip code of a bunch of missing zip codes in the US

We're using MapPoint to export zip code / territory combinations. Unfortunately, the export doesn't include PO Box zip codes which mean that we're missing a lot of zip codes The PO Box zip codes are ...
1
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0answers
66 views

Assign a IGeometry to Feature.Shape

I'm trying insert a feature into a FeatureClass, but when I try to assign the geometry to featurebuffer the app return the next Error: The remote procedure call failed. (Exception from HRESULT: ...
1
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0answers
69 views

QGIS 2.4.0 doesn't support multiple types of geometry in GML file

I'm testing GML 3.2.1 data according to INSPIRE Data specification (version 3.0). Data for theme Cadastral Parcels shall have both polygon geometry and definition point. When I download data from my ...
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0answers
26 views

Buffering/extrusion of a dem surface

I have a surface representing a DEM and i would like to add it some thickness. If i simply duplicate the surface and translate it down by my thickness, i get non uniform thickness, ie thinner where ...
1
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0answers
63 views

Why does the postGIS file lose geometry?

I am loading shapefile data from a GPS into PostGIS via Leica ZenoOffice. This apparently imports fine with it's geometry in the attribute table. However, when I add a postGIS layer in QGIS the file ...
1
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0answers
83 views

v.clean in QGIS Python console

I have tried to use v.clean and v.clean.advanced (by GRASS GIS) within a script in QGIS, and was not able. I followed instructions here:, but was not able to do so. I got message: "No module named ...
1
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0answers
341 views

Invalid geometry

I'm working on some shapefiles in both ArcGIS 10.2 and QGIS 2.0. I have 3 files which I have cleaned of self intersections in ArcGIS using Repair Geometry. I have also checked for Overlaps using the ...
1
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0answers
202 views

How to force geometry type in (WFS) layer in QGIS

I have an external WFS source serving mixed geometry types - in other words, I have no control of the source. When adding the layer QGIS sets the geometry type to line and thus I am unable to style ...
1
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0answers
54 views

PostGIS automatically creating geometries after importing using QGIS DB Manager

I have a shapefile consisting of linestrings, in which some of the features have null geometry. Yet, after importing it to PostGIS, using QGIS' DB Manager, a geometry is created for those features ...
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0answers
67 views

Merging parcels but keeping Geometry seperate

I am working on updating a parcel layer we received for a project, and I have duplicate parcelID's for parcels and I have been merging these to create 1 parcel as to not have duplicate ID's. My ...
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0answers
179 views

Using M 'Measure' value in SQL Server 2008

MS Sql Server 2008 geometry type supports adding Z and M values to geometry objects, including linestrings. However, I cannot find any way to make use of these values, since methods such as ...
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152 views

Error When Generating INSERT Statements for Geometry Field SQL Server

I am populating a column of linestrings from a list of points in sql with which I use to create insert statements to populate an ID and a geometry field in a table. This creates a temporary dataset ...
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0answers
156 views

Inaccurate result while clipping on gis data

I am trying clip polyline data using a polygon geometry. I am using itopologicaloperator to do this task. However, resultant clipped data is off by 1 feet. Meaning that the polylines at the boundaries ...
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0answers
195 views

pgRouting results to LINESTRING geometry type

I am doing some routing queries, using pgRouting's second version of pgr_trsp function. What I can't do effectively yet is storing the results. That is, I want to able to store in a table: either ...
1
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0answers
35 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 ...
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0answers
182 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 ...
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0answers
93 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 ...
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0answers
117 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 ...
1
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0answers
125 views

Geoprocessing operations re-introduce geometry errors after “repair geometry” succeeds

I am working with a shapefile that has many small, detailed polygons. After exporting it to a feature class in a geodatabase, I found that some operations (for example, Snap in the Editing Toolbox) ...
1
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0answers
94 views

Calculating spaces between roads from PostGIS database

Is it possible to calculate the spaces between the roads using a select statement in a PostGIS/PostGre Database? I tried using some combinations of the predefined functions as ST_Intersects & ...
1
vote
0answers
329 views

Create IPoint with Lat/Long in decimal degrees and Z in feet

I have written an ArcMap v10 AddIn that reads a folder of geotagged JPEG's and creates a new feature class where each point is the geotag information from on of the JPEG's. The issue is: The GPS ...
1
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0answers
264 views

Problems with Multipatches

I have some polygonal features that have minimum and maximum z values. I'm trying to calculate the difference between a fixed extruded polygons and the sum of extruded related polygons. Here's how ...
1
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0answers
715 views

ArcGIS 10.0/arcpy: Can't retrieve the points in a polyline geometry obect: any idea why?

My arcpy script builds a Python dictionary, dictCLPnts, that holds the geometry objects of a polyline feature class. The following code snippet shows the attempt to access the geometry object with ...
1
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0answers
278 views

Export topology tables to txt files using ArcObjects, generating directed graph, and finding intersections

I want to export topology tables to text files: for points: 1 id x y for lines: line id fompoint.x from point.y topoint.x topoint.y for polygons: id line id 1, line id 2... 2 arc ...
0
votes
0answers
45 views

MS SQL table with geometry field to feature class

I have a table in a native SQL database (no geodatabase, dc_geobank_public.sde in the code) with cca. 300 000 records and 18 fields. Two of the field contains projected X and Y coordinates, and one ...
0
votes
0answers
30 views

ArcGIS Desktop: Not Rendering Line Data but Web Service Outputs Fine

I have some script which read .JSON files through .NET and then inserts the data into a SQL Server database. The data's Geometry is of the type esriGeometryPolyline ; basically, they are floor plans ...
0
votes
0answers
34 views

Explanation of the Thinness ratio formula?

I am looking for sliver polygons and am using the following formula to identify which polygons have a smaller area-to-circumference ratio (aka Thinness Ratio): 4 * pi * area/(length*length) That ...
0
votes
0answers
74 views

Efficient way of determining polygon intersection with bounding box

I have a set of polygons, and I need to check whether they are intersecting with a given bounding box(rectangle). What I am doing is, I am taking every vertex of polygon and checking whether it's ...
0
votes
0answers
78 views

Google's S2 library - any alternatives?

Is there any alternative to Google's S2 geometry library? It looks it was updated 4 years back and hardly any documentation. I need a library to divide cities into zones of the area I need. S2 looks ...
0
votes
0answers
51 views

Drawing boundaries between discrete features based on attribute values in ArcGIS for Desktop?

There is a point feature class with a certain numeric attribute (let us say, populated places with population). I wonder if there is, in ArcGIS, a way to draw polygons such that the sum of the ...
0
votes
0answers
41 views

Joining the tables with the geometry

I have a large table (as a shapefile without geometry, just set of records) with data which has the refference to the other tables (as a shapefiles with specific geometry, reference as same ID's for ...
0
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0answers
34 views

Points contained in envelopes that cross date-line - java

I'm using the ESRI Geometry Java API https://github.com/Esri/geometry-api-java I want to construct an envelope and see if it contains certain points. It's possible the envelope crosses the ...
0
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0answers
40 views

Transforming GIS based XY data (polygons) so that they overlap in R

So I'm attempting to come up with the average shape of these polygon features as a part of my masters research. To do this, I want to run a shape analysis of GIS-based X-Y data using the shapes ...
0
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0answers
16 views

postgis 2.x geometrycollection and multi

I want to gather differents geometries in a table. So I transformed a multipolygon geometry in a geometrycollection. Now if I can insert differents geometries, I lost the capability of insert ...
0
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0answers
41 views

JTS Geometry to GML3.1 encoding

I searched all the internet and I didn't find a solution to my problem. I want to convert a JTS geometry to a GML3.1 geometry. Geo tools says that have support but the have not (please check encode ...