(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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0
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1answer
192 views

ST-Links convert Feature Class to DB Table error

I'm using ArcMap with the ST-Links SpatialKit Conversion tool to convert a Feature Class to a DB Table. But I'm getting an error: ERROR: 42601: type modifier is not allowed for type "geometry". I ...
2
votes
1answer
364 views

Reading OGC geometry data from SQL server using R

I would like to write a script in R that creates a map using OGC geometry data that is stored on a Microsoft SQL server. Is there a way to read OGC geometry data using a query passed from R? Maybe ...
2
votes
1answer
489 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 ...
0
votes
2answers
261 views

Calculating area gets a different result

I've calculated the area of polygons with QGIS by using ctr-i - geometry - $area. I've set it on real. The results seem fine, but I've noticed they differ from the area given when I use the ...
2
votes
1answer
4k views

Making POINT from longitude/latitude coordinates in existing table using PostGIS?

I would like to make a POINT using the longitude and latitude columns of an existing table. Here's a link to the documentation of ST_MakePoint. Here's my table: CREATE TABLE sysinst.bio ( oid ...
2
votes
1answer
513 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. ...
0
votes
0answers
67 views

How to populate polygon extents to an attribute table in QGIS

Is there a way to calculate the XMIN, YMIN, XMAX and YMAX of a polygon and write it to a field in an attribute table? The Geometry functions available in the Field Calculator are for points. ...
2
votes
1answer
108 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 ...
0
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0answers
73 views

Retrieving ArcGIS:s Spatial Data into a Database

Background: If you have created a vector map with lots of spatial data in geometry flat in with measurement kilometer. The following object that is used in the map will be point, line and polygon ...
0
votes
1answer
103 views

Is it possible to have measurements in centimeter and decimeter in 2D flat (geometry)?

Is it possible to have measurements in centimeter and decimeter in 2D flat (geometry) for ArcGIS?
3
votes
1answer
85 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 ...
2
votes
2answers
157 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
2answers
507 views

arcobjects update geometry Z values of line vertices with a given number

I am trying to develop arcgis 10.0 addin to update Z values of vertices of a selected line. Scenario: The tool scans all features in a given shape file and populates the list of features which has at ...
3
votes
4answers
412 views

What Application for Vector and Cartesian Coordinate System

Goal: Visualize a picture in SQL server 2012 spatial data based on geometry Problem: In order to display a vector picture I need to retrieve X, Y coordinate (cartesian coordinate system) and ...
1
vote
3answers
137 views

How to Retrieve X and Y from a papermap or gif picture

Goal: Visualize a subway map in SQL server 2012 spatial data based on the map of the subway. The map shall use geometry, traffic rail road as line object, station as point object and zon as polygon ...
4
votes
2answers
356 views

PostGIS algorithm to unite points of two geometries that are within specified radius

I want to find an PostGIS algorithm to unite points of two geometries that are "near" to each other. That is: I want a function, that takes as input two geometries, and returns 1 geometry, that ...
4
votes
2answers
3k views

How to calculate distance between two points with esri.geometry?

The function http://help.arcgis.com/en/webapi/javascript/arcgis/jsapi/#namespace_geometry/esri.geometry.getLength should calculate distances between points. When I am trying to calculate distance ...
1
vote
0answers
111 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) ...
0
votes
1answer
573 views

how to find vertices for a geometry in OpenLayers

I am having a LineString, where I need to find the vertices logically and save those vertices. Can anyone help me out. Or else how below can help me. OpenLayers.Geometry.LineString = ...
2
votes
1answer
360 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
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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?
3
votes
1answer
474 views

Geometry Conversion Problem

How do I convert from an ESRI.ArcGIS.Geometry.IPoint to an ESRI.ArcGIS.Client.Graphic point object? In other words, I'm wanting to convert from an IGeometry to a runtime geometry, I guess.
3
votes
2answers
239 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 ...
3
votes
2answers
518 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. ...
5
votes
0answers
189 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 ...
2
votes
3answers
603 views

arcpy: get list of adjacent lines per line

I am working with polylines with hundreds of thousands of features, and would like to write a script that returns the OIDs of all lines adjacent (intersecting with) each line. I have been ...
4
votes
1answer
526 views

How to find the nearest polygon from a given point?

Basically I have set of points [lat-long pairs] which defines different polygons on map. Now I have a coordinate [lat-long] from which I want to find the nearest polygon from that point. Any help ...
8
votes
2answers
1k views

Nearest point on a line ( Spherical / Mercator projection )

I have a line (Ax,Ay - Bx,By) over a mercator projection (google maps) and a random point (Cx,Cy) nearest to that line, i would to know the closest point (transparent blue on the image) over that line ...
13
votes
5answers
411 views

What in-depth spatial database systems tutorials exist?

Is there a good tutorial that explains in depth the internals of a GIS and a spatial database system such as PostGIS with examples and without any background assumption? I'm specifically looking for ...
5
votes
1answer
108 views

Should the geometry column always be the last column of a postgis table?

When we need to add an attribute to a table (e.g. a table of 350,000 polygons), my instinct is to always recreate the table so that the geometry column is last. I think this is a best practice for ...
1
vote
1answer
298 views

“There is not enough memory” Error when accessing IArea.LabelPoint

I have an intermittent error that I'm having a terrible time tracking down so I thought I'd see if anyone has encountered something similar. I am trying to access the label point of a polygon feature ...
8
votes
1answer
304 views

How to rank polylines according to their similarity to a ref polyline?

How to rank polylines according to their similarity to a ref polyline? Update 1: simulations show that simple $\sqrt{\sum{(case-ref)^2}}$ can find better similarity between polylines (as set of ...
5
votes
1answer
311 views

How do you fix Overlapping Lines?

I have a line dataset that contains some lines where the "end points" are actually found in the middle of the line. In the image below, the nodes are shown in green and one of the end points in red. ...
3
votes
1answer
604 views

Join attributes by location

I am trying to join multiple records that occupy the same location (polygon centroid) and have tried using the join by location plug-in but have found this does not work for me in this case as I have ...
4
votes
2answers
1k views

postgis error: when adding features geometry has z dimension but column does not

I have to define a geometry column in PostGIS for 2D points, but when I try to import points from DXF to postgres I get the following message: "postgis error: when adding features geometry has z ...
6
votes
2answers
1k views

Calculating a spherical polygon centroid

I'd like a general way to calculate centroids for polygons on a sphere. So far, the best online reference appears to be: Tools for Graphics and Shapes by Jeff Jenness. The method described ...
5
votes
1answer
789 views

Python: find a method to calculate the “inner centroid” (also known as labelPoint in arcmap) of a polygon

i am looking for a method to compute the X,Y coordinate of a inner point (also known as labelPoint in arcmap) of a (irregular) polygon. I am try to find a solution without the use of ArcGIS module ...
2
votes
1answer
2k views

How to fix incorrect SRID of the geometry column? [duplicate]

I've been told to use AddGeometryColumn to properly add a column with correct/preferred SRID. however I wonder if it's possible to fix/change the current column instead of adding a new? If there's no ...
1
vote
2answers
593 views

dealing with 2 different coordination systems in postGIS

I'm seeking a function that converts degrees to the following format: POINT(405115.926025391 4543389.4354248) I dont know this format's name, but is there any function to do so? Cheers, EDIT ...
11
votes
4answers
14k views

How to get coordinates from geometry in PostGIS?

This line: SELECT geom FROM myLayer.geom will return a hex value, i'm wondering how would it be possible to get decimal values, a result that look likes human-readable coordination? Regards,
3
votes
4answers
1k views

What is the easiest way to detect geometry type from text in PostGIS?

I have some records with different types of 'geometries (poly,line,points)' stored as string. I'm trying to use ST_GeomFromText as I want to do some intersection with them. What is the easiest way to ...
4
votes
1answer
187 views

Tunnel distance approximation

Having two points (longitude, latitude) on earth, if I am sure their distance is under 100 km; how much error will I have using tunnel distance approximation? (Defined at here) Note: Currently I am ...
2
votes
0answers
159 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 ...
21
votes
1answer
695 views

Space filling between random 2D lines

Consider a region (2D) filled with lines randomly (following Figure). We are interested in filling the empty spaces between lines including four boundary edges in a way: 0- maximizing the size of ...
3
votes
2answers
642 views

How to find self-intersecting polylines using ArcObjects?

If I have a polyline, how do I figure out whether it is self-intersecting? I tried to use ITopologicalOperator.IsSimple Property, but it always returns true. Are there any ways of doing these kind ...
6
votes
3answers
274 views

What geometric attributes do polygons possess, and how can these be used to filter features?

Given a polygon featureclass containing many polygons of different sizes and shapes, which geometric attributes (area, perimeter, etc) could be used to filter the polygons? It's probably best to ask ...
3
votes
1answer
193 views

Road layers appearing as points in GeoServer previews - both openlayers and GeoExp

I am wondering why my roads layer keeps appearing as points when previewed inside GeoServer - layer preview using both the OpenLayers and GeoExplorer options. The data are imported from PostGIS. I ...
2
votes
1answer
374 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 ...
12
votes
4answers
1k views

How can one compare two geometries in arcpy successfully?

I am trying to compare two separate feature classes to identify differences between them (sort of a diff function). My basic workflow: I extract the geometries using a SearchCursor Save the ...
12
votes
3answers
2k views

Self intersections for polygons, how to solve?

I have a question about repairing a self intersecting polygon shapefile. I have a shapefile containing Polygons (ZM) which have self intersecting features. If I use the "repair geometry" tool, it ...