Tagged Questions

Version 2.0 of PostGIS brought a heavy set of new extensions for the PostgreSQL object-relational database, adding greater support for spatial objects.

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1answer
39 views

How do I convert MultiLines to MultiPolygons using Postgis

In postgis I'm using the following query to buffer lines to polygons: UPDATE rivers SET poly = ST_Multi(ST_Buffer(lines, 0.01)) where id = 1; The column 'lines' is a MultiLine and the column ...
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0answers
26 views

Joining layers with respective elements with PostGIS Topology

Recently I have started using PostGIS topology extension, but I have some difficulties in understanding how the structure works: One of the key points is the use of "layer"s: as of what I understand, ...
2
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1answer
33 views

How to connect Postgis database with/in Remote Servers…?

I am preparing a 'Web based map' application using 'Geoserver-Openlayers-Postgis'... Now, I am trying to connect my Postgis database(located at 10.50.110.11 location) with the following command from ...
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0answers
18 views

error in loading raster tiles on postgreSQL

I am trying to import raster data from PostGIS to GeoServer. I follow the instructions given on this link. ...
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0answers
15 views

Get Complete Details Of Raster Column in the Raster Table

i'm having the geotiff files containing the details of the temperature of the specific co-ordinate value along with it. Configuration details: Postgresql 9.2, Postgis 2.0, GDAL 1.9.2. Here my ...
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3answers
48 views

Snapping start- and end nodes of lines to other lines in PostGIS

There are plenty examples that show how to snap lines to points, but I haven't been able to find any (fast!) way of snapping the start- and end nodes of line strings to nodes of other lines. ...
0
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1answer
62 views

Emergency Services: How to optimize routing by measured travel time?

I would like to optimize the service areas / catchment areas for an emergency service. Therefore, I have several measurement points on the streetmap, where people have stopped the travel time from ...
3
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0answers
53 views

How to install PostGis on EC2 micro-instance

I tried to install PostGIS on my Amazon EC2 microinstance using sudo yum install postgis2 and got following error message: $ sudo yum install postgis2 Loaded plugins: ...
2
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1answer
58 views

Calculating points in the USDA's Cropland Data Layer coordinate system

I need to integrate against the USDA's cropland data layer. They've got a demo and some API docs. The important query I need to run is this, given an (x, y) of say (1551459.363, 1909201.537): ...
1
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1answer
41 views

Getting a “java.lang.OutOfMemoryError” error while importing raster files from PostGIS to Geoserver

I am trying to import raster data from PostGIS to GeoServer. I follow the instructions given on this link. ...
1
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0answers
35 views

operator does not exist: geometry <#> geometry

I'm running PostGIS 2.0 for PostGreSQL 9.2, and I have a customer who wants to know how close a provided geometry is to the nearest feature in a table. So I'm playing around with the "<->" and ...
2
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1answer
28 views

Are there strategies for dealing with TopologyException errors in PostGIS 2?

Are there strategies for dealing with TopologyException errors in PostGIS 2? Nearly every function I run against two geometries results in a TopologyException (e.g. ST_Intersection, ST_SymDifference). ...
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1answer
40 views

Postgis 2: Polygon/MultiPolygon in a single column

Storing MultiPolygon and Polygon features in a single column used to be as simple as not creating or removing the geometry type check constraint. Is there a similar simple fix in PostGIS 2?
0
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1answer
22 views

ImageMosaic-JDBC Error

I'm trying to get postgis raster layers in geoserver-2.3.1, with postgresql-8.4, postgis-2.0 and gt-imagemosaic-jdbc-9.1.jar support. I'm going through the tutorial with a PNG raster that i have. In ...
3
votes
1answer
36 views

How can I check if a multipolygon can be represented as a simple polygon?

I have a large (30m+ records) spatial data set I have imported into a PostGIS database. I did not expect to find multipolygons in the data set, but it does have a few of them. I'd like to take a ...
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0answers
21 views

not able to import raster data through raster2pgsql [closed]

I'm new to postgis and I'm not able to get through raster2pgsql. The problem is: I want to import a raster (.tif) file using raster2pgsql. But after running the command: raster2pgsql -s 4326 -I -C ...
2
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2answers
97 views

PostGIS: Convert meters to arbitrary spatial reference units?

I'm writing a query that needs to be able to work with data of any SRID. The basic problem is very simple - I get two pieces of information: A point (SRID = 900913) A distance (unit = meters) I ...
2
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1answer
55 views

How can I make a Postgres/PostGIS ST_Distance_sphere query more efficient?

Within Postgres/PostGIS I have written an SQL query to get the closest distance for each element within a point coordinate table from a polyline table. The query comes back and works correctly, but ...
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0answers
35 views

tinyows failing to connect to postgresql - Ident authentication failed for user “postgres”

I'm getting the above error on a new and local tinyows installation on Centos 6. Postgresql 9.2, PostGIS 2.0. I can connect to PostGreSQL locally and from my LAN using several other methods (psql, ...
2
votes
1answer
66 views

Cannot find my schemas in QGIS's “Add PostGIS layers”

When I connect to my PostGIS database using QGIS's Add PostGIS Layers, I see only public topology pg_catalog information_schema My other schemas that I have created are not shown here. Anyone else ...
0
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1answer
77 views

How to split line layer at polygons' boundary of a polygon layer?

I have a line layer and a polygon layer in PostgreSQL 9.2, PostGIS 2.0. How can I split every line each time it crosses a polygon's boundary?
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1answer
29 views

How to update SRID in PostGIS database

I am facing a problem when I am trying to execute few queries in PostGIS. It returns the following messages. ERROR: GetProj4StringSPI: Cannot find SRID (4326) in spatial_ref_sys ********** ...
4
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4answers
186 views

Unable to connect Postgis from QGIS 1.8.0

I have installed PostgreSQL and PostGIS on my laptop (Win 7 64 bit OS). I am running QGIS 1.8.0 on my machine . When I am trying to connect Postgis I am getting connection failed error then I tried ...
3
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1answer
41 views

PostGIS: Merge multiple table with same GID

I just imported some shapefiles with the PostGIS importer. Because several errors and issues I had to split my shapefile in multiple parts. Then I imported them one by one. I thought I can easily ...
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2answers
171 views

How to draw line in leaflet using postGIS road data

I have few points from server and I want to draw a line with this point on road. But the leaflet drawing point to point line as shown in picture in orange color. But I want to draw the line ...
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0answers
44 views

How a PHP script can perform point, line and polygon operation on Geoserver and PostGIS (+wkt) [duplicate]

I want to show my shape file and LULC map (vector and raster data) on internet explorer (locally). How should I configure PHP and Geoserver so that I can show data on localhost on an IE or browser? It ...
0
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1answer
68 views

How to show PostGIS distance in Meter

I have calculate distance from one point to a linestring. I have used the following query WITH data AS ( SELECT geom::geometry AS road_network from linestring) SELECT ...
2
votes
1answer
85 views

PostGIS ST_Contains question

Here's a quick summary about what I'm trying to do: Let's say I got two layers. One (A) with 10 polygons and one that is more granular with 100 polygons (B). Just to check if the behavior of PostGIS ...
3
votes
3answers
114 views

How to find lat/lon values for every pixel in a GeoTIFF file?

I want to a store GeoTIFF file pixel by pixel in the database. I need to store pixel values along with the lat/lon of that pixel on the GeoTIFF image. Is it possible to do that?
2
votes
1answer
351 views

Can POSTGIS 2.0 be install with POSTGRES 9.2 on Ubuntu 12.04 OS at the moment?

This question is more about environment set up. At the current moment, March 4th 2013, can POSTGIS2.0 be install with POSTGRES 9.2? I check their website out and to my understanding it is not ...
2
votes
1answer
113 views

How to import ECW into my postgis database with raster2pgsql (windows)

I'm working on windows 7 64 bits, postgis 2.01. I have to import ECW files into my postgis database. Unfortunatly, my postgis seems to has been compiled without gdal ecw support.When i do a ...
11
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1answer
158 views

Naming conventions PostGIS Database

We are starting to build up a database with PostGIS. The database is supposed to be for a team of about 5-8 researches who work frequently with geodata and statistics. Has anybody experience with ...
1
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0answers
103 views

How to import 3D geometries from DXF, VRML or X3D into PostGIS 2

we plan to develop a webbased 3D GIS using PostGIS 2 and GeoServer with a W3DS. The architecture works fine, but i have problems to import 3D geometries into PostGIS. The geometries come from AutoCAD ...
0
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1answer
75 views

How to properly use PostGIS with Maps

First time using PostGIS in an app. Target: - Get Heat Map of customers from address table using leaflet.js and heatmap.js Have DB called store_dev. Installed OSM Bright from Mapbox in it. Have a ...
3
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0answers
63 views

PostGIS 2.0 st_geomfromgml using LineString fails with invalid GML representation

I am attempting to insert a geometry into a table using the st_geomfromgml function. The GML is being sourced from a Geoserver WFS request. The function call looks like this ...
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0answers
56 views

ST_intersects and shortest_path to optimize routing in respect to (de-)acceleration

Is there a way to consider a more complex cost field in the PG_Routing algorithm? I am currently trying to get more realistic routing costs. I have a map based on the German ATKIS standard with road ...
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0answers
21 views

Weird behaviour of ST_Project with PostGIS2

somehow I can't understand the results of ST_Project, but maybe this problem is just me being stupid (again): Note: I use geography-type here, but the results are the same for geometry. I use a ...
2
votes
1answer
123 views

generate height data from DTED maps

I have 16 DTED maps of (1 degree x 1 degree). I have to generate combined height matrix of maximum 4 (1 degree x 1 degree) DTED maps in my C++ application. Can someone suggest to me which open source ...
1
vote
1answer
147 views

Dynamically load and display shapefiles from PostGIS 2.0 into Mapguide using .NET

I have a C# mechanism for Loading shapefiles into PostreSQL/PostGIS now I would like to dynamically load it on Mapguide fusion template.In either C# or VB.NET code behind. Use case is: 1.use uploads ...
2
votes
1answer
55 views

problems setting up postgis and importing data

Using Postgres 9.2.3.1 on a new Mac. I installed Postgres from the dmg file that I downloaded from the Postgres site. I then installed PostGIS using stackbuilder. This all worked flawlessly so far ...
1
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0answers
63 views

Renaming Columns in Geotools FeatureType

I am attempting to build a simple java program that loads shapefiles into a Postgis 2.0 database. Everything is working out great except that I would like to be able to modify the FeatureType in the ...
2
votes
1answer
81 views

How to Find the Nearest Node from a Given Coordinate

I have already developed a table manually. It contains the coordinates and the distance of all the nodes, there is no geom field or any field related to postgis. But I want to find out the nearest ...
3
votes
2answers
255 views

PostGIS - incorrect result distance between two points

I am quite confused the way PostGIS is returning the result for this basic query. So I am trying to find the distance between two points 45.2714,71.2087 and 42.3739,66.39 and the distance should be ...
3
votes
1answer
133 views

Using PostGIS for a large trajectory dataset

I have a spatial trajectory dataset which basically contains about 10E6 (lat,lon,time)-tuples, grouped together by an identifier so they form trajectories. Currently, SQLite is used to store the raw ...
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0answers
51 views

Create Polygon Overlay Handling Holes

How can I create a polygon overlay that correctly handles holes? This answer provides a method of creating a polygon overlay that does not handle holes. Can it be modified to correctly handle holes? ...
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0answers
16 views

Aggregation operation on raster files inside a raster database in postGIS Raster

I have a raster database in PostGIS Raster. I want to merge a number of raster files that are imported to the database using average to create another file. In the other words, the mean value of ...
5
votes
1answer
246 views

PostGIS SQL query to find a polygon that intersects with a line

I need to build a PostGIS query that would select every polygon inside an area the river is flowing through. I'd better describe with an example below: There is a river (blue line) flowing through ...
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0answers
50 views

how to group interconnected edges inside a table?

Given a table and a random set of edges with source and target columns, how can I find out which edges connect with each other and then group them together using PostgreSQL?
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0answers
39 views

given sets of vehicle passing on each edge, how to get most used vehicle to avoid transition?

I have two tables: one, the resulting table from converting osm.xml via osm2po so I can use pgRouting, and another one that contains information on what edges each public vehicle passes through ...
3
votes
1answer
153 views

Transit Routing using pgrouting as core routing engine?

i'm a student and i'm working on a project. the aim is given two sets of coordinates(origin & destination) route through the map to determine the optimum path using public transportation and of ...

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