PostGIS is an extension for the PostgreSQL object-relational database that adds support for geographic objects.

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332 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
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3answers
387 views

Adding a GIS feature to existing database entry with QGIS

I've built a database with postgreSQL with tables, which include geometry columns. When I add some data to my non-geometry columns, I can see them in QGIS when I connect to my database using postgis. ...
0
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1answer
102 views

ST_Dump not working with geometry_dump

I am trying to ST_Dump a geometry_dump column comprised of points and paths in PostGIS 2.0 using SELECT (ST_Dump(geom)).geom FROM pointdump However, I get the error message 'function ...
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2answers
64 views

Where to type pgsql2shp command

How to convert post gis database into shapefile, I found that I need to use pgsql2shp command on postgis database query , But how to use it and where to use it. Do I have to use it in the postgre sql ...
0
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1answer
41 views

Rollback error when restoring SQL dump file in postgresql using PSQL console via Pgadmin

I am trying to restore a pg_dump SQL file into my postgresql database using PSQL console , where I typed the below command: \i 'c:/../path/to/sample.sql' when I run this I get an error saying ...
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21 views

at which location to run psql2shp command in linux [duplicate]

I have linux system which I have connected remotely and I am not able to use $psql2shp command in the command line. I went to /usr/local/pgsql/data to run the command but I was unable to run. I dont ...
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2answers
334 views

In PostGIS, how do I merge a multilinestring into a single linestring, keeping the pieces in proper order?

I have a multilinestring made up of several pieces, some of which are facing the wrong direction. (Accessible here: http://pastebin.com/89Zcixv5 ) I think what I'm looking for is some utilization of ...
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1answer
131 views

Geoserver OSM data Imported via osm2pgsql - most efficient tables to use to style roads

The Osm2pgsql importer for OSM data to Postgres results in two tables for ways, one called planet_osm_roads and a second one called planet_osm_lines The Osm2pgsql documentation states that the ...
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1answer
140 views

Difference between 2 projections?

I have osm.xml file where projection is defined as follows: Map background-color="grey" srs="&srs900913;" minimum-version="2.0.0"> n settings.xml file projection is also set there as: <!ENTITY ...
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2answers
407 views

Importing MaxSea 3D Database to PostGIS

I am currently working on a project, where I combine several MaxSea 3D databases, which contain depth measurements made by the echosounder onboard on a ship. The idea is to combine these databases to ...
3
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2answers
734 views

Rendering geoJson polygons in google maps android apiv2

I'm in the process of publishing spatial data stored in a postgis database to a google maps based android app and am trying to put together a plan for rendering my data in the most efficient manner ...
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3answers
211 views

adjusting polygons to boundary and filling holes

here's the problem: Where: 1: department boundary 3: polygons inside department boundary that "touch" the department boundary(1). They are not necesary fitting well inside 2: holes between 1 and ...
2
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1answer
32 views

How to populate geography point using ST_MakePoint(long, lat)

I have a table called customer_campaign, and there is an empty column geom(geography) in it. So I want to fill it up by using ST_MakePoint(long, lat) in PostGIS, lat and long are two columns in the ...
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0answers
34 views

Geoserver ( Java.exe ) cause server to run 100%

Our server runs at 100% CPU when using map services build on geoserver + postgresql I can not find anything in geoserver logs. It is Java.exe takes 100% CPU and because of that server can not do ...
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3answers
99 views

How to export streets in a certain area from one shapefile to a new shapefile?

I have a shapefile with the roads from Europe and I want to export in a new shapefile only the roads from Greece. I tried to delete the other roads but there are too many and I have no attribute to ...
0
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1answer
177 views

ArcMap reports that PostGIS polygon data is self-interescting

I have an ESRI File Geodatabase of data that I upload to PostGIS using FME. Seeing as I have to have the data in PostGIS for other purposes, it would be great to view the data in ArcMap straight from ...
1
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1answer
28 views

How can I strip out M values from a MULTIPOLYGON with PostGIS?

The title is self-explanatory. I wonder if there is a simple function like ST_Force2D for the M values?
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2answers
98 views

Split lines at intersection points

I've got some linestrings covering a road network, and need to split them at the crossroads. Does anybody have any idea on how to do it? I'm using QGIS 2.4, with a Postgis 2.1.3.
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2answers
228 views

Create multi-line from point in PostGIS

I'm working on an old table where polygons are stored as points. Now, I want to migrate these points to PostGIS and store them as polygons (or multi-polygons). The table structure is as follows: ...
1
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1answer
92 views

Get a single cluster from cloud of points with specified maximum diameter in postgis

I have on the order of 2M Geometry Collections with N (median: 2, stddev: 6.6, 75th: 6, 95th: 21) Point objects (repeated points allowed and important) in a PostGIS table. I want to identify clusters ...
41
votes
4answers
11k views

Spatial clustering with PostGIS

I'm looking for spatial clustering algorithm for using it within PostGIS-enabled database for point features. I'm going to write plpgsql function that takes distance between points within the same ...
7
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2answers
336 views

How to avoid duplicate GIDs when copying features from one PostGIS layer to another?

When I enter new elements (features) in another Postgres layer, I can do it in two ways: Drawing new element(s) (with 'Add feature') which I do rarely or Copying (or cutting) some elements from ...
2
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1answer
50 views

Positons from GPS lanes inside a polygon

i have a lot of lanes like the orange lanes at the below picture (latitude and longitude values). Now i need all values from each lane inside the red polygon. What is the easiest way to realize ...
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1answer
176 views

Setting up PostGIS: Postgres can't see the PostGIS extensions?

I've just installed Postgres 9.3.4 and PostGIS 2.1 on OSX Mavericks using the very latest versions of the KyngChaos libraries. This is a new machine, and I deliberately haven't installed Postgres ...
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0answers
31 views

Clustering the WGS84 point features (projection transformation aspects)

My question is quite trivial and was discussed many times before (like here) but in our case it has the confounding extra requirements... The list of sparsely distributed 2d point features is stored ...
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0answers
58 views

All map services display pink tiles

I have implemented mapserver in Ubuntu 14.04 with postgresql 9.3, postgis and imposm using GitHub tutorial. After completing the tutorial all map services display pink tiles not map info. i was not ...
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1answer
120 views

Create shapefile from data PostGIS or KML using Java

I'm working on a geographic information system project, whose products form shapefiles. I am using the Java programming language and a PostGIS database. Is there a way to generate a shapefile from ...
3
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1answer
108 views

Routing problem finding shortest route to line

inspiration on how to solve this problem. (Ascii art, I don't have points to insert picture) I need to find Z Z = Shortest route from X Using Road (no point exists here) O = The points that makes ...
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0answers
39 views

Rebuilding a Polygon from the points within it, in PostGIS

This question is an update on the problem formulated here. I wanted to redefine the border of a set of polygons, in order to "smooth it". My first approach (described in the former question) was to ...
2
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1answer
43 views

Redefining the border of a polygon in Postgis

I have a PostGIS algorithm that writes a table with "pixelated" polygons, that I will call "clusters". My idea is to smooth the edges of these clusters using concave hulls (ST_ConcaveHull). To do ...
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2answers
35 views

How to get the tripoint of three or more polygons in PostGIS?

Assume that I have a column containing polygons. What is the SQL statement to get the list of points that three or more polygons touch with each other?
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16 views

ArcGIS dissolve analysis output issues in geoserver wfs/ PostGIS

I have an ArcGIS dissolve analysis output (parcel data) that needs to be loaded on PostGIS and published as a wfs from geoserver. The issue is that the ArcGIS dissolve output shapefile, although can ...
6
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1answer
151 views

How to use ST_DelaunayTriangles to construct a Voronoi diagram?

With PostGIS 2.1+ we can use ST_DelaunayTriangles() to generate a Delaunay triangulation, that is a dual graph of its Voronoi diagram, and, in theory, they have an exact and reversible conversion. ...
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1answer
135 views

Import DEM into PostGIS for QGIS

I'm a complete GIS newbie so sorry if I'm using the wrong terminology in searching for a solution to this... I'm trying to import a DEM into PostGIS and display it in QGIS. The data is from the EU-DEM ...
2
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2answers
46 views

Did I set up Tiger Geocoder incorrectly?

I set up Tiger Geocoder in PostGIS on my local box (PostGIS 2.1.3, PostgreSQL 9.3.5, Tiger 2013 data). The problem I'm running into is that on almost every street most of the points are clustered, ...
2
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1answer
41 views

Why does the earth drop off faster than expected over a geodesic when converting from lat/lon to cartesian coordinates?

In PostGIS 2.1.1, I've been plotting elevations from a raster over distances, but noticed that beyond 1km, the earth's curvature seems to be greatly exaggerated. In this example over a 40km geodesic ...
2
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1answer
49 views

Databases supporting intersection of multipolygons and a set of points

Currently we use PostGIS to store thousands of MULTIPOLYGONs and we can then use ST_Intersects to return any that rows contain any point in an input collection of points. Are there any other open ...
3
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1answer
96 views

Postgis 2.0 geographic polygon has max longitudinal range

My problem is that I have a load of geographic point data (srid 4326) in a table. A user may do a bounding box search - essentially create a polygon as follows: l_poly geography(Polygon,4326):= ...
3
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4answers
270 views

Heat map / Density map from dynamic points table in MapServer (GeoServer)?

How can I create a heat map (some would call a density map) from a points layer in MapServer (or GeoServer)? (preferably able to choose Interpolation method, NN, IDW, etc and color map with a ...
2
votes
1answer
204 views

Automated correction of parcel geometry based on area measure?

i have a set of parcels in DWG file and i have the areas that should be in these parcels in an excel file, so i have to modify each parcel to match the area specified in the excel file with a moving ...
4
votes
1answer
1k views

Union, Dissolve, Buffer — multiple layers, all in one step?

I'm a new user of Quantum GIS (1.7.3) and I need to repeat a task multiple times, so I'm wondering if there is a quicker way to do the following (with three or more polygon layers - each layer has a ...
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0answers
66 views

QGIS WFS Error - Could not commit changes to layer

I have a PostGIS database being served by Geoserver. I can load the layers I want into QGIS no worries; however whenever I try to edit the layer I get this error message: Could not commit changes to ...
3
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4answers
1k views

Calculate min distance between points in PostGIS

I have point layer in PostGIS database. Help please with query which add for each points in layer distance in attribute table between this point and another nearest point. Thanks! Update Calculate ...
2
votes
1answer
197 views

CartoDB “Error loading rows, check your SQL query” & “There is a pb with your connection”

I have been trying to install my own CartoDB server for a few weeks. I succeeded to install each part with no error (after few corrections) with this tutorial. Make check with CartoDB-SQL-API and ...
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0answers
41 views

List of vector to one raster in PostGIS

Hi PostGIS developers! I need to rasterize a part of OSM map by coordinates. I found rather good algorithm, but can’t finish it. I have problems in STEP 3. I described all algorithm here – may be ...
0
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1answer
98 views

Drawing curved lines in CartoDB?

I am experimenting drawing curved line from Origin to Destination in Cartodb. I was able to do so once, however, failed the second and third time. Could anyone offer me some insights into the ...
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0answers
57 views

Intersection of a vector linestring and underlying DEM

Following is an screen-shot where ASTER DEM raster layer has been overlaid by a road linestring vector layer. I want to extract those DEM pixels which are lying exactly beneath the linestrings. I want ...
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2answers
199 views

Editing PostGIS topology in a web browser

I am trying to conceptualize the best process for editing topology from PostGIS in a web browser. Ideally what I would like to accomplish is the loading of a topology (imagine the lower 48 states of ...
3
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1answer
43 views

Bounding box of a set of MULTILINESTRINGs PostGIS

I have a PostGIS table with a geometry column (geom) and a type column. The geom column contains only MULTILINESTRINGs and the type column contains tags that tell me what each MULTILINESTRING ...
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0answers
10 views

Get a geometry point along a line from another point with distance using OGC SFSQL

I am wondering is that any quick OGC SFSQL function (or any other spatial query) which return a geometry point that: The point is x distance along a line from its A-End ? ps: I am using postgis 2.x