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

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how to identify EPSG of any shapefile [duplicate]

I have a shape file, imported in PostgreSQL using PostGIS when this shape-file is published in Geo-server it didn't show any layer. I had used EPSG:4326..thanks
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181 views

Spatial Precision for Editing in Multiple GIS Clients

I have something I'd like to discuss, I'll try to explain it first, why it's important, and I'll explain how ArcGIS handles the issue, which I think is a good way to handle it. Finally I'd like to ...
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1answer
282 views

Polygon grid shape file for landmass

I am interested in generating a polygon grid shape file for the landmass of the world. What I have presently is two tables in postgreSQL. Table 1: Coastal area shapefile ...
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56 views

How do I make vectorlayer with sql on PostGis via python code

I need to make a vectorLayer and fill with the SQL's results on PostGIS via python code. I'm working with python 2.7, QGIS 1.8 and PyQt 4.5 How do I it ? thanks
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430 views

Loop though records in PostGIS (using PL/PYTHON or PGSQL)

I've seen many example of loops, but I can't get that one to work. I work for a regional transit agency and each year, we conduct several surveys. I geocode everything to the house level for internal ...
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43 views

What is the meaning of “MULTIPOLYGON EMPTY” Message?

I am trying to run ST_Intersection function. SELECT ST_AsText(ST_Intersection(ST_Point(42.729123082000058,-96.619302355999992), ST_Point(42.72899715300008,-96.619410439999967))) FROM clu_08aug; I am ...
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158 views

Strange exposure of a PostGIS layer in QGIS after importing OSM data into a database

I've imported a osm layer into my postgres/postgis database. osm2pqsql -E 3857 -c -S /usr/share/osm2pgsql/default.style -H localhost -W -d landslide -U postgres oberpfalz-latest.osm.bz2 During the ...
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3k views

PostGIS: Count number of vertices of lines and polygons in tables

I have 23 tables in a postsgis schema which I need to count the number of vertices of. The tables are a mixture of lines and polygons so realised I need to use ST_NPoints(geom) So I ran the following ...
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2answers
768 views

How to convert shp to PostGIS dump?

Given a file my_file.shp such those from Gadm e.g. US administrative divisions, where the coordinate reference system is latitude/longitude with WGS84 datum. Input could actually be: Shapefile, ...
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39 views

How to make a vectorlayer through of sentence SQL on PostGRES

How do I create a vectorlayer to through SQL on PostGiS on Python 2.7. I is working with QGIS 1.8 and I needed create a vectorLayer through SQL on PostGIS.
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2k views

Are there open source solutions for travel demand modelling?

I'm looking for open source tools for travel demand modelling (eg The four-step UTMS). Preferably in a GIS environment. That works well with Qgis, Grass and Postgis. My question is not related to ...
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662 views

save features from openlayers to postgis via nodejs and websockets

I try to save features created on a vector layer (openlayers) to postgreSQL 9.1/postGIS 2.0 via websockets. As server I use nodejs 0.10.12 along with the pg module I cannot fix it. Its getting so ...
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1answer
116 views

Multiple Rasters into PostGIS

This may have been asked before, but A) what software/libraries etc do I need to B) load multiple rasters into PostGIS? I have Python 2.7.5, QGIS 1.9 (latest Weekly Build), PostGIS (whatever the ...
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1answer
144 views

Spatial Aggregation of attributes from line structures in polygons

maybe someone has an idea how to deal with it (or directly knows the equivalent functions in PostGIS) for the following problem: I have a transport network (something like railways) and the ...
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2answers
382 views

nearest neighbor with postGIS and nodejs

I'm using postgreSQL 9.1 , postGIS 2.0, nodejs 0.10.12 and the latest version of node's pg module. I use websockets on the server side. I implemented a function that tries to find the 5 nearest ...
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2answers
820 views

How to create a MultiLineString feature with a postgis layer in QGIS

I have troubles handling with MultiLineStrings in QGIS. I added the table where I defined a column as geometry(MultiLineString, 31468) as a postgis layer in QGIS. Now I want to create features with ...
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1answer
464 views

Why won't OGR connect to my PostGIS database, but QGIS will?

Trying to connect to my PostGIS database with some success... One hiccup is that OGR will not connect to my server from a remote machine, though QGIS can connect to it just fine from that same ...
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4answers
956 views

How to use PostGIS to handle complex geoprocessing workflows?

Our organization is considering moving our geoprocessing workflow to PostGIS. We are currently using ArcGIS, with a plethora of custom Python tools used in ModelBuilder. We're moving most of our data ...
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1answer
325 views

Maritime route prediction avoiding land masses

I am working on a project where the following functions have to be implemented: Predicting the locations of the ships (in maritime environment) at a future time. (Can be done with Kalman filter, IMM ...
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1answer
101 views

st_intersects on postgis

I'm trying to write a command to see whether a given point lies within a multipolygon boundary (in this case, a watershed). I have a table of watershed boundaries and another table with the point I'm ...
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63 views

What is the MS SQL Spatial syntax for counting points within polygons? [duplicate]

All, What I'm trying to do is this: Count points within polygons There are thousands of points and maybe 2 dozen polygons Get a list back of the 2 dozen polygons by name and the count of points ...
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1answer
1k views

OS Vectormap GML files into PostGIS

I am having difficulty in efficiently dealing with OS Vectormap data that comes in GML format. In the past I used the Plugin for QGIS (OS GML Tools) to batch convert folders of compressed GML (.GZ) ...
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418 views

MapServer Clustering GetFeatureInfo

I'm having a bit of a problem with clustering in map server the clustering itself works fine and the GetFeatureInfo works fine most of the time. However some times when I click on a cluster point it ...
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2answers
3k views

How to select all points within a circle in PostGIS?

I have set of points in a PostGIS Table (Type Geometry). Now, I need to filter points that lie in a circle with a center (C) and radius (R)! I expect C to be of type Point or Coordinates.. R to be ...
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725 views

Very poor performance of QGIS and PostGIS2. User error or feature?

I have a large table in Postgis2. It has >500 million polygon, line and point features all happily living in there and the table performs brilliantly in other GIS. I am now trying to just add that ...
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306 views

How does geoserver determine what SRID to pass to PostGIS [OPERATION ON MIXED SRID GEOMETRIES]

We are using Geoserver to render some data onto maps in a web application. The map shapes are read by Geoserver from a postgis database. The shapes are imported into postgis using the ogr2ogr utility. ...
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94 views

Intersecting Layers Returns Empty Collection Despite Visible Intersection

When I perform an intersection of a polygon I draw in OpenLayers and a postgis database layer, it seems that I am getting incorrect results. Intersection works correctly on some layers. For ...
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538 views

How to render GPX files in TileMill?

I want to show a number of GPX files in a TileMill map. Here's the process that I thought would work: gpsbabel -i gpx -f "$myfile" -o kml,lines=1 -F "$myfile.kml" Add as layer in Tilemill, style ...
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3answers
245 views

What is gid in OpenStreetMap data model?

I'm using an old code written by an ex-fellow and I wonder what is GID in OSM? The gid is basically used everywhere. The project uses PostGIS and PgRouting. Any pointers to that? I know this is a ...
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153 views

Large buffers in PostGIS (5000 km radius)

I have a number of points stored as geographies in PostGIS (version 2.0.1), and I'd like to create rather large buffers around them (with a radius of 5000+ km). However, ST_Buffer doesn't handle this ...
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467 views

PostGIS package problem on Ubuntu 12.04.2 LTS

I've started getting an error on Ubuntu when trying to upgrade packages: "Not all updates can be installed Run a partial upgrade, to install as many upgrades as possible" When I run a partial ...
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197 views

can Geocat Bridge enable me to connect to existing PostGIS database and make edits through ArcGIS?

We are planning to set up a Webgis to share our GIS data on the web. Currently, we are on a desktop GIS and using ESRI's File geodatabase format. We are considering ArcGIS Server or using Opengeo ...
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1k views

PostGIS: Inserting a null value into a geometry column - feasible?

I'm trying to insert a null value into a geometry column, which I cannot do: "ERROR: parse error - invalid geometry" So what I'm trying to accomplish is to erase a point from a map and save that ...
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268 views

Using pgr_drivingDistance with large ids

I have little experience with postgres and none with pgrouting. I'm trying to use the pgr_drivingDistance function with Open Street Map data (generated through osm2po), but whenever I run my query: ...
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1answer
2k views

Setting coordinate system in PostGIS

The geographical information data that INEGI (part of the Mexico's goverment) provides are in the following coordinate system (or is projection?) Lambert Conformal Conic, double standard parallel ...
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3answers
1k views

Why can't I open postgis layers in QGIS?

I've set up a table in PostGIS using OSM data (converted using osm2pgsql). I know this database is good, because I'm able to import it and work with it in TileMill, but whenever I try to interact with ...
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393 views

3D features (Polyline, Polygon) intersection library

For my research I am looking for a (python) library to get the intersection of some 3D features. The features can be Polygons or Polylines. Mostly I need to intersect a plane with my features and get ...
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706 views

Are there Desktop GIS alternatives to ArcGIS 10.X for topology and vector conflation?

Is there any options other than ArcGIS for Desktop for topological rules and automatic topology integrity enforcing in a Desktop GIS? I am looking for something that will automatically snap features ...
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1answer
67 views

Compare features in PostGIS with updating attributes

I have two polygonal layers: "existing" and "modified". Attribute table of "existing" and "modified" layers have same column "feature_id" - number of feature. Please help me create query which write ...
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73 views

QGIS Gazetteer Plugin connection to internal database

A few posts on here mention that the Astun QGIS-Gazetteer-Plugin could be adapted to reference a PostGIS database. Has anyone done this adaptation and could share it? I want to use a gazetteer stored ...
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1answer
379 views

PostGIS 2.0 ST_Split rounding errors when splitting line with point

My apologies for the bad title; I couldn't think of anything more descriptive. I have been testing ST_Split with a dataset, and found that even with points that are supposed to be exactly on a line ...
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115 views

Can I speed up very long connection times to a PostGIS DB caused by complex views?

When connecting to a PostGIS database to add a postgis layer, all table and views are scanned by Qgis in order to define the geometry type (if I understand well the query performed). My problem is ...
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19 views

Estimation of Net Primary production (NPP) [duplicate]

I want to study calculate NPP of my city. Can you teach me how to do it? And can you advise me any softwares and models to caluculate NPP? If it possible write full instruction!
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487 views

Find points that fall within a radius using Hibernate Spatial

I am using hibernate spatial and postgis and i want to find the points that fall within a certain radius. Using this SQL: SELECT name FROM institution WHERE ...
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1k views

Version editing for Postgresql 9.2.4 / postGIS 2

Background: I am "building" a GIS with PostgreSQL 9.2.4 / PostGIS 2 as the database and QGIS 1.8.0 as the geographic application. There will be multiple users accessing, editing and viewing the data ...
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64 views

Can't edit osm_roads in udig

There is a PostGIS database that has a road network imported from Open Street Map, stored in osm_roads table. For the testing purposes I need to change some road geometry there. I tried to edit it ...
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1answer
3k views

PostGIS 2.0 “No function matches the given name and argument types”

After a lot of research, I figured out how to build PostGIS 2.0 from source on a Turnkey Linux LAPP (Postgres 8.4) server. The main draw of PostGIS 2.0 for me is the ST_ConcaveHull function, aka ...
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1answer
358 views

PostgreSQL/GIS table relations in QGIS 1.8.0

I am building a database in PostgreSQL 9.2 with the PostGIS 2.0 extension. The database consists of a schema called Water which contains water related geographic features (as example, boreholes and ...
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927 views

What to do if PostGIS gives error that “geometry requires more points”?

I have a .TAB file. I convert it to ESRI(shp)-->sql and insert it into database. Using PostGIS when I want to convert the data into ESRI file, it shows an error: geometry requires more points ...
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111 views

PostGis functions vs. EWKT [duplicate]

While using PostGis, we can query using EWKT format like: SRID=4326;POINT(lon lat) or use the functions defined by PostGis itself. For example: ST_SetSRID( ST_MakePoint( lon , lat ) , 4326 ) I'm ...