(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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0answers
3 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
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1answer
87 views

Radius of curvature for curves in road segments for entire road network

I have a road network shapefile for a US state and I am trying to derive the radius of curvature for road segments in this shapefile. I need to be able to perform this task within just a few functions ...
3
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1answer
83 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 ...
1
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1answer
42 views

Is there a PostGIS function to get a tangent and normal line?

I'm looking for a function that will return a tangent (and normal) for a LINESTRING in PostGIS. I think this is the 3rd time I've come across the need for this function and everytime, I end porting ...
0
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1answer
90 views

Invalid geometry message when using Difference tool

I am using the Vector \ Geoprocessing \ Difference tool to get the resulting area when taking a) current ground disturbance away from b) historic total ground disturbance to give c) what has been ...
0
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2answers
142 views

Calculating minimum/maximum width for overlay of two polygon strips in ArcGIS or some Opensource GIS

Is there some solution for calculating minimum and maximum width for overlay of two polygon strips? When I clip these strips the result is another strip with variable width about 1 km and 20 km long. ...
4
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1answer
176 views

How to calculate X and Y projected coordinate in batch processing

I have more than 1000 shape files (all are point features). They were initially in WGS 84. I projected them in UTM. Then through batch processing I added X, Y fields in each table. But all the X, Y ...
1
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1answer
246 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 ...
2
votes
1answer
41 views

Delete duplicate polygon nodes with PostGIS

I'm trying to delete duplicate nodes from a shapefile with QGIS, but after running the tool to delete it, nothing happens and shows the same errors. I thought that maybe importing to postgis could be ...
0
votes
1answer
15 views

ValueError when instantiating LineString from a mix of tuples and Point objects

I'm new to Shapely, and tried instantiating a LineString object from a mix of tuples and Point objects like this: >>> LineString([Point(1,2),(2,3),Point(3,4),(5,5)]) I get the following ...
2
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1answer
60 views

Removing last point in polygon geometry using ArcPy?

This polygon was created from a grid of 500 x 500 meters, then Union, Generalize and Dissolve was used to arrive at this geometry, the laspoint not help me, I just want to have points on each vertex. ...
0
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1answer
30 views

WKT: What is the reasoning behind the concept of a POINT EMPTY?

In data formats like WKT and WKB, we have ways of representing "empty" geometries. That all pretty much makes sense: a "LINESTRING EMPTY" is a LINESTRING type with 0 vertices. Same with a MULTIPOINT, ...
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1answer
92 views

using Z and M feature geometry to create line graph in Python?

I am a Python (v2.6.5) noob trying to plot a series of 3D polylines into graphs. So far I've come up with: # Import system modules import arcpy, os, sys, string from arcpy import env ...
2
votes
3answers
52 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 ...
5
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2answers
579 views

IFeatureClass.Search throws error “0x80041599 The number of points is less than required for feature”

I am creating a buffered geometry around a point feature in order to search for other nearby features. I use the TopologicalOperator to create my buffered geometry. I am attempting to search a feature ...
0
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1answer
186 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 ...
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1answer
40 views

Buffering a PointGeometry in arcpy only returns a line?

I am trying to buffer a PointGeometry object in arcpy to a Polygon geometry object with ArcGis 10.2. The PointGeometry object is in lat/lon WGS84 coordinates and as far as I understand, I can only ...
1
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1answer
34 views

Get coordinates from polygon outline with greatest distance

I'm looking into a task in ArcGIS 10.2 of which I need to discover the two points on a polygon outline where they would be at the greatest distance from each other. I have looked at ET Geowizards ...
1
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1answer
28 views

GeographyFromText and ST_SetSRID+ST_MakePoint different results?

Why am I getting different results? SELECT ST_DISTANCE( ST_GeographyFromText('SRID=4326;POINT(13.401111 52.383343)'), --berlin ST_GeographyFromText('SRID=4326;POINT(9.997559 53.533778)') ...
0
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1answer
122 views

SQL Geometry Query similar to Select by Centroid

Does anyone know if it's possible to query SQL geometry by something like 'centroid of polygon'...similar to ArcMap's select by location? I'm using SQL Server 2008 R2 as the DBMS. I have two polygon ...
0
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1answer
100 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?
2
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1answer
31 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 ...
0
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1answer
42 views

Openlayers WMS getFeatureInfo get features with geometry attribute

I am displaying map using WMSlayer and implemented WMSGetFeatureInfo control on wms layer. Tap on a location and get the features using WMS getFeatureInfo service. This service is returning me all ...
5
votes
3answers
717 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 ...
0
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1answer
42 views

PostGIS change column type varchar => geometry

I have a Postgres database with PostGIS extension on it. Also, I have a table with column lat with type (varchar 40). Column values are like this: 52.1432514 52.1431855 52.1431586 I want to convert ...
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2answers
37 views

Calculating Centroids with Zonal Geometry in ArcGIS

I have a shapefile containing polygons. Each polygon is defined by its postal code. I want to calculate the centroid of each polygon using Zonal Geometry. Sadly, for some polygons there are no ...
11
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4answers
2k views

Comparing two Digital Elevation Models (DEMs) from LAS files?

I have two Lidar las files, one is original let's say with X points. And the other is copy of the first las file but with Y points, where Y is less than X. Now, I want to compare how the Digital ...
0
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0answers
6 views

Convert Surface to MultiSurface in SQL Server

I need to create view where geometry column is MultiSurface datatype. But, column in my table is Surface datatype. Is there any chance how to convert single Surface column to MultiSurface column ...
0
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2answers
84 views

Python library or algorithm to generate arc geometry from three coordinate pairs?

I'm trying to write code to generate fixtures for a django/geodjango project. I need to generate geometry for arcs (line string) given three lat/long pairs; start of arc, end of arc and centre of arc. ...
0
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1answer
23 views

Not empty geometry having blank text

i'm having problem with geometry column, for some rows i have geometry with blank text, this query will describe more the problem : select geom, ST_AsGeoJSON(geom), ST_Isvalid(geom), ST_IsEmpty(geom) ...
0
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1answer
28 views

ArcObjects - Geometry type select with Vbnet

How can I read the geometry type of shapefiles with ArcObjects and Vbnet? I want to check whether it is a point, polygon, or a line.
3
votes
2answers
56 views

ArcPy Data Access Insert Cursor not writing geometries to feature class?

I'm running ArcGIS 10.2.1 and am having troubles with the Insert Cursor in the arcpy module. I have an empty feature class in my geodatabase and have created the short script below to try and find the ...
2
votes
2answers
152 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 ...
0
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0answers
14 views

Find Coordinates of Larger Area from Sub-Areas

If I have the sets of coordinates of the borders of some sub-areas is there a way to calculate the overall border of the total area? (The coordinates are 2D Cartesian coordinates.) E.g. if I have the ...
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 ...
2
votes
1answer
44 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 ...
1
vote
3answers
244 views

Merge Multipart Feature Line

I'd try to merge multipart feature line, but didn't work. would you please teach me how to merge multipart feature line? I work in version environmental and geometry network. Regards,
2
votes
1answer
106 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
votes
0answers
18 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 ...
0
votes
0answers
26 views

USA MSA/City/County with SImplest Border in JSON

I deal with a lot of poloygon-related JSON representing US places regularly. One thing that could make reading JSON with my eyeballs easier is having a short list of US places whose borders have ...
1
vote
0answers
89 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
vote
2answers
954 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 ...
3
votes
2answers
613 views

Way to Ensure that the Image Centroid is Within Image Bounds

My application uses the ArcGIS Silverlight API to select polygons from a map layer. It uses the Geometry.Extent.GetCenter() method to get the centroid of the shape and add a thumbtack image at those ...
1
vote
0answers
41 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 ...
0
votes
1answer
22 views

Geometry conversion problem.Data loss

I was trying to convert a roadnetwork table.Its geometry contains both MULTILINESTRING and LINESTRING.I converted all the MULTILINE string to Linestring using the query update all_india_merge set ...
1
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1answer
36 views

Test for polygon orientation

I'm want to merge multiple geometries with Geotools (starting off with one geometry) but the result is a polygon that has a clockwise orientation. This gives a invalid geometry. My code for the merge: ...
1
vote
1answer
47 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 ...
0
votes
0answers
59 views

Prevent self-intersecting loops when exporting polygon layer from ArcSDE to File Geodatabase?

I am using ArcGIS 10.1. The source data is housed in an ArcSDE instance that does not allow self-intersections. When I export this data to a file geodatabase and run check geometry ...
0
votes
1answer
42 views

Difference between 'point' and 'WKSpoint' in ArcGIS

I have to add 3-D points to make a polygon in ArcGIS using VB.NET. I have defined an IpointCollection and want to add points to this. I have options to add 'point' or 'pointcollection' or 'WKSpointz'. ...
3
votes
4answers
392 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 ...