(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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1answer
259 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 ...
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 ...
0
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1answer
13 views

Add Marker on the polygons' centre using Openlayers?

I have written a code to draw polygon from the WKT format.Now I need to add the marker at its centre. In the following code I have passed the centre and shape in WKT format(extracted from database). ...
2
votes
1answer
66 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 ...
3
votes
1answer
45 views

Extract longitude latitude and radius from POSTGIS column

I have entered the circle in the Geometry type column (name=shape) in my POSTGIS as following: ST_Buffer(ST_MakePoint($longitude, $latitude)::geography, $radius)::geometry Then I extracted the ...
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1answer
32 views

PostGIS get geometries within a radius of n meters using WGS84 [duplicate]

select * from zones z where st_intersects(z.geom, st_Buffer(ST_SetSRID(ST_Point(2.336031, 48.863172), 3857),1)); It looks like the 1 in the st_buffer is being interpreted as degrees, I need to find ...
2
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1answer
56 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 ... ...
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1answer
33 views

selecting elements of a specific geometry type in PostgresSQL/PostGIS

I was reading a postgis tutorial and noticed that unlike working with shapefiles, one can actually store different types of geometry in postgres. In a table created with multiple geometry types, the ...
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0answers
17 views

.geojson extension file is wrong [closed]

Sorry whats wrong with this file http://eric.clst.org/wupl/Stuff/gz_2010_us_040_00_20m.json I found it and i need this to submit an app to the apple store, but looks like uploading this file as ...
9
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2answers
901 views

why do people use geometry to represent geography?

Historically I've mainly worked with simple latitude and longitude coordinates in a SQL Server. I stored them as a geography datatype in SQL Server, and rendered them on a variety of displays ...
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1answer
47 views

Is it possible to draw polygons along Google Maps Polyline?

Web application has option that user draws polyline on Google Map. After he draws it, there is a button 'Add polygons', which should draw polygons along that line, based on some width and height in ...
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0answers
18 views

Tools to generate all the possible geometries meeting specific constraints

I have an area = 2d polygon (generally a 4-side shape). I would like to generate all the possible rectangles matching the following constraints: that fall within the surface of the area with a ...
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2answers
152 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. ...
1
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1answer
28 views

Set default projection of geometry objects in arcpy

I have a script that creates a polyline geometry from scratch using some math to generate coordinate pairs. At the same time, there is a user-defined polygon shapefile that is used to "erase" the ...
2
votes
1answer
679 views

How to draw polygons from the python console?

I've been visiting and revisiting the page on geometry handling in the PyQGIS Cookbook: https://www.qgis.org/en/docs/pyqgis_developer_cookbook/geometry.html but can't seem to figure out how to get the ...
3
votes
1answer
364 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 ...
0
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1answer
229 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 ...
2
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1answer
329 views

Multipoint vs point PostGIS

Is it normal to use the geometry type 'multipoint' instead of 'point' knowing that I use it to store only one point. How can I convert from multipoint to point
0
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1answer
103 views

Get the vertices on a LineString either side of a point (Sql Server 2008)

I have a point that sits on top of a LineString, both Sql Geometry types. POINT('0.5 0.5') LINESTRING('0 0 NULL 1, 1 1 NULL 1') I want to find the vertices of the LineString that lie either side ...
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0answers
24 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 ...
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 ...
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0answers
20 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 ...
0
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2answers
108 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 ...
1
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1answer
43 views

Get geometry from OpenLayers.Control.WMSGetFeatureInfo JSON

I need to store the geometry of a certain feature with OpenLayers.Control.WMSGetFeatureInfo and i'm using these parameters to get it in json format output:'features', infoFormat:'application/json', ...
1
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1answer
20 views

Changing order of parts in multipart geometry using ArcGIS for Desktop (or ArcPy)?

Is it possible in ArcGIS to change order of the parts in multipart geometry? In the context menu i founded "insert before" , "insert after" but it never comes active ... or is it possible via ...
0
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1answer
135 views

Using Z and M feature geometry to create line graph in ArcPy/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 ...
6
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2answers
761 views

Get shortest distance between two geometries in ArcPy

I'm using ArcPy and using a cursor to step through one polygon feature class. For each of these 'source' polygons, I am creating a SearchCursor to find all polygons in a second feature class that ...
0
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0answers
93 views

TileStache : Unknown geometry type in geoJSON file

I'm currently trying to set up a TilSstache server on Ubuntu 12.04 to serve some GeoJSON tiles from a shapefile/JSON file (administratives boundaries) for a web mapping project using the Leaflet ...
2
votes
1answer
42 views

Calculating geometry area in ArcGIS for Desktop using ArcPy?

I have a polygon shapefile and I want to write a Python script to add a field named "area" and calculate its geometry areas. The script is like this: ...
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0answers
43 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 ...
3
votes
2answers
8k views

How I get SRID from Geometry field

what is the function for getting SRID from Geometry field. I have inserted a shapefile into SQLServer table with Geometry field defined. I know the projection of shapefile is Swreff99_1800 ...
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2answers
95 views

Export polygon in geojson as multipolygon

Anyone knows if is there any way to export a polygon layer in geojson, as multipolygon? I have a multipolygon shapefile. But there are single and multi polygons. When I export it to geojson, I got ...
0
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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?
1
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1answer
32 views

Geometry error in roadnetwork

I have a road network table. When I check st_isValid(the_geom)='f', I am getting an error: NOTICE: IllegalArgumentException: point array must contain 0 or >1 elements ERROR: Exception in ...
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 ...
1
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1answer
37 views

Rotating geometry to specific angle using pyqgis?

I do not know how to rotate a geometry using pyqgis. Is there any sample/example code available to show me how?
2
votes
1answer
136 views

Converting set of points to polygon using C#?

I want to convert a set of gps ponints to polygon.I used a simple loop to convert it to a WKT and than used makevalid() in sql server and save it in a gemetry column in databasae.Is this way right?or ...
0
votes
0answers
16 views

Drawing geometry and attaching it to featureclass with arcobjects and Add-in button

I am newbie to ArcObjects and exploring classes. I want to have form created on add-in button click.(Form contains certain text boxes for input) That shall create a new feature class and then allow ...
1
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1answer
30 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 ...
6
votes
2answers
640 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 ...
4
votes
2answers
49 views

Map location of unknown point with distances to two known points

I'm trying to develop a function in R that will locate a point (A) on a map given distances between that point A and two other points (B and C), for which exact coordinates are known. The problem I'm ...
3
votes
4answers
145 views

How to fix quickly a lot of geometry validity errors in QGIS?

I am working on ownership data at a US county level. I have one shapefile per county that contains thousands of tax parcels. I need to dissolve the polygons representing parcels owned by the same ...
3
votes
1answer
59 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 ...
2
votes
1answer
28 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
165 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 ...
1
vote
1answer
48 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 ...
4
votes
1answer
210 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 ...
2
votes
1answer
53 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
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1answer
21 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
69 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. ...