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

learn more… | top users | synonyms

1
vote
2answers
61 views

PostGIS ERROR: getPoint4d_p: point offset out of range

I have a set of streets (LINESTRING) in a PostGIS 9.1 PostGIS 2.1 database. I need to obtain points from the lines, on the right and on the left of the street. I offset the lines with: ...
1
vote
1answer
98 views

Finding closest Intersection between line strings (PostGIS)

I want to find the distance between one point (excavation sites) and a line (rivers) for the cardinal directions. What I thought would be the easiest way is to draw lines between the excavation site ...
0
votes
0answers
49 views

OpenStreetMap Road and Polygon Data as 1x1 Degree Shapefiles

I am working on a global project for which I want to use OSM data as a model input. I am looking for advice on the best way to produce 1x1 degree WGS84 shapefiles from either regional extracts or the ...
1
vote
1answer
56 views

ST_Union to merge tables containing lines?

I have to build a street network with Postgis that will be used with pgrouting. I have two tables: 1) the_network (182 lines): is a MULTILINESTRING table. Having columns road_name (varchar) / ...
0
votes
0answers
21 views

Credential Dialog, disabling default Realm information messages disclosing password

I'm using the QgsCredentialDialog for determining user access to the database. When a user is failing to log in correctly the log in credentials are shown in the dialog (Fig. 1). (success, uname, ...
0
votes
1answer
43 views

Self organizing maps with Postgis

I am trying to plot hot regions. It's reorganizing mapping We have a table "product" with three attributes : lat log n_items: number of items that we sell I'd like to group point in one polygon ...
1
vote
1answer
40 views

Trying to understand / troubleshoot intersection behavior of postgis

I'm trying to calculate the percent of intersection between two polygons using postgis. I was able to do so successfully for 90% of my polygons, but about 1500 have very unexpected values. I ...
4
votes
1answer
158 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
votes
1answer
119 views

ST_Buffer returns inaccurate results with radius of over 1 meter

I have a specific location: lat, lng and accuracy(meters) I want to return a geography object that will represent a polygon that surrounds this point with a given radius that will be equivalent to ...
2
votes
2answers
106 views

Extract a PostGIS dump from OSM with a particular tag

I'm new to OpenStreetMap. I want to extract all restaurants from Switzerland with their capacity if available. I am using osmosis. I tried: osmosis --read-pbf file=switzerland.pbf --tf accept-nodes ...
1
vote
1answer
41 views

Weird ST_Contains behaviour

I'm creating a polygon and then checks whether one of the origin points is contained inside the polygon. To my surprise, I get False (?!) What is wrong here? SELECT ST_contains(ST_GeomFromText('POINT ...
1
vote
2answers
57 views

Can 'Source' and 'Target' in the roads table for routing be duplicate?

I am using pgr_ksp for finding multiple paths for single source and destination. I am wondering if 'source' and 'target' in a roads table are unique or not. because when i am doing routing on my road ...
0
votes
0answers
14 views

Query from plugin that shows result on Map and in Attribute Table

I'd like to create a plugin that performs a static (no user input required) query that, based on a condition, selects all the features on the map and displays these in the attribute table. I have the ...
0
votes
1answer
53 views

PostGIS transform geometry with long crs

How do i transform a geometry to a new geometry with a crs like urn:ogc:def:crs:EPSG::25832 st_transform(geom,integer srid) obviously doesn't work since my srid is a string found a solution ...
2
votes
1answer
79 views

How to set tolerance value of ST_Intersects query in TileMill?

I want to place river names in Tilemill. I use "text-dy" to displace label from the center line of a river. But for labeling polygonal rivers, names extracted from lines are used too. So at a small ...
1
vote
1answer
93 views

How to cluster similar lines in PostGIS?

In PostGIS I have a large database of linestrings which I have obtained using ST_makeline function. I would like to cluster similar lines based on where the lines start and end. Here is an example ...
0
votes
0answers
34 views

How to get create new object right in postgresql

I created a .shp in QGIS successfully and now i want to move on this to postgis db, following this command shp2pgsql -s 2964 roads.shp lakes_new | psql qgis_db but i got this error how to solve ...
0
votes
1answer
88 views

Error with Gdal 1.10 install on Ubuntu 13.10

I've installed GDAL 1.9 then upgrade to 1.10 on Ubuntu 13.10 and then now it's error (gdalwarp can work but gdal_translate is fail) gdal_translate ERROR 1: gdal_translate was compiled against GDAL ...
4
votes
1answer
126 views

Configuring Geoserver to use a specific postgis geometry column as the default

I have a PostGIS table with two geometry columns, both multipolygon but one with SRID 4326, the other 3857. When publishing the table in Geoserver, I realize that Geoserver defaults to using the first ...
2
votes
2answers
125 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 ...
1
vote
1answer
111 views

Routing in MS SQL 2012

I would like to perform routing in MS SQL 2012 similar to pgRouting. In pgRouting, I'd do the following steps to create a routable network: Create a database routing with template template_routing ...
2
votes
2answers
150 views

Identifying the cause of NOT ST_IsValid()

I have a table of raw GeoJSON in a Postgres database, with PostGIS installed. Some of this GeoJSON is unfortunately invalid, for varying reasons. SELECT id, name, geometry FROM shapes WHERE ...
3
votes
1answer
79 views

Split lines at intersections in PostGIS (must be simple but…)

I'm usually closer to my answer than now, but I've looked at all the answers here and couldn't adapt one to work on my data and I'm stuck. I have oriented polylines (Montreal's train network) and ...
3
votes
1answer
154 views

Improve speed of PostGIS “nearest neighbor” query?

One of the features of the Python/Django/PostgreSQL web application I'm building is that a user will be able to see the 100 other users who are nearest to them, sorted by distance. I'm using PostGIS ...
1
vote
0answers
29 views

Problem installing Aggregate Polygons Function in PostgreSQL 9.3

I'm new to PostgreSQL and I've been trying to run a sql function written by Dr. Horst Duester, found in http://www.kappasys.ch/cms/index.php?id=65&L=5, which is used to aggregate detached ...
2
votes
1answer
83 views

polygons and lines not drawn correctly (qgis+postgis)

i am really new to this so i could use some help.. i load osm file into postgresql and then i connect to the database with qgis t to plot it and i see this it happens to whatever file i import to ...
1
vote
1answer
142 views

QGIS/PostGIS layer styles

I've made a plugin asking for login credentials to a DB. Once logged in, the plugin is loading some layers from the DB. In the DB there are both admin and "normal" users. I've saved two styles to the ...
1
vote
0answers
60 views

Geoserver WFS Fails to Load in OpenLayers

I'm working with Postgis->Geoserver->openlayers on localhost. I followed a Geoserver tutorial to import some nyc sample data into my postgres/postgis database and link it to Geoserver. The layer ...
1
vote
0answers
22 views

ST_SplitRight() in PostGIS?

I am looking to split a shapefile via a line. I am interested only in the feature that lies to the right of the line; exactly what ST_SplitRight does here. Do any of you know of a way to do this in ...
0
votes
1answer
52 views

How to solve an instalation problem requiring “liblwgeom” to work with “shp2pgsql”

I am trying to import shape file to postgis. I have problem configuring shp2pgsql. I am getting this error : dyld: Library not loaded: @loader_path/../lib/liblwgeom-2.1.1.dylib Referenced from: ...
0
votes
0answers
47 views

PostGIS: calculate width/length of rectangular surface

I have rectangular shaped surfaces (multipolylines) and I need to calculate the width and/or length.. they have a rectangular shape but they're not real rectangles. Is there a way to do this ?
0
votes
1answer
33 views

Postgis add Geography to function()?

i was wondering im getting different results when using geography() on different positions within a query. So, whats the most accurate way of forcing geography() over a functions with geometry ...
2
votes
1answer
125 views

System requirement specification for Big Data Postgesql, PostGIS, and GeoServer based service

I want to start a GIS portal for around 3000-5000 visitors per day. MY database will be of an approximate size of 10 Terrabytes. The maps and layers are moderately complex, satellite-map overlay is ...
0
votes
0answers
67 views

PyQGIS loading layer style with PostGIS

I'm loading layer styles from .qml files in a Python plugin. I'm about to switch to loading them from a non-local postgreSQL db. I've been looking at the (from QgsVectorLayer (v2.2)) ...
0
votes
1answer
48 views

Increase Map Availability in Geoserver [duplicate]

I have an application which access same map from two geoserver using loadbalancing concept the map is accessed using WMS service. where the two geoserver connected to a single same POSTGIS database. ...
2
votes
2answers
88 views

What is wrong with how I am using ST_Within?

I am learning postgis 2.1. I created a postgis table from a shapefile and imported it into the DB. It made a table like this: db=# \d districts ... geog | ...
-1
votes
2answers
137 views

can't geocode with PostGIS 2.1.1

I don't know where's the mistake... I am using the process from the PostGIS documentation (http://postgis.net/docs/manual-2.1/postgis_installation.html#loading_extras_tiger_geocoder) . I created a ...
3
votes
2answers
128 views

ESRI projection to SRID?

I am looking at MapX and MapY coordinates. The docs say they are "truncated State Plane coordinates: NAD 1983 State Plane Louisiana South FIPS 1702 (US Feet)." I am trying to reproject into a common ...
0
votes
0answers
29 views

Double version of PostGIS installed on my server

For some reason I messed up an installation of Postgis on my PostgreSQL 9.2.8 server. I had version 2.0.3 installed and when I tried to upgrade to 2.1 it did so. The problem comes when I dump the ...
0
votes
0answers
136 views

PostGIS 2.1 error install with shared object (rtpostgis-2.1.so") Linux Mint

I've Installed Linux Mint 16 mate and install PostGIS with PostGreSQL (I've tried many ways in the Internet from original source to some suggestion) but all is too error: " ERROR: could not load ...
2
votes
0answers
51 views

PostGIS does not export shortest path to Shapefile

I am trying to draw a bunch of lines overlaying the globe map in a WGS84 projection. To this effect I have created a PostGIS DB with a table that has one column containing linestring data. My problem ...
0
votes
2answers
601 views

How to install PostGIS and OpenLayers plugins?

I am new to QGIS and have installed the QGIS v 2.2.0. For adding google map as a base layer I need to install OpenLayers plugin. I also need to add the PostGIS plugin for DB management purpose. Can ...
2
votes
1answer
86 views

POSTGIS: function st_collect(geography) does not exist

I am trying to use some Geography functions, but I am getting an error that (all) functions are not existing. I have checked other Stackexchange posts (e.g. this one), but the solutions did not work ...
3
votes
2answers
77 views

How <-> operator work?

I'm doing a search to find links close to a point. The problem is if i limit to 20 result i found the closer link at 6mts but if i limit to 10 result that link doesnt appear and the closest link is ...
2
votes
1answer
57 views

Can you do ST_Transform on geographies?

I am brand new to postgis. I just learned that geometries model simple cartesian objects and that geographies model shapes on the surface of the earth. I have a bunch of data in columns X and Y of a ...
3
votes
2answers
202 views

How can I GROUP BY linear spatial clusters with PostGIS?

I have a series of points in a horizontal line, arranged into discrete spatial clusters by the underlying data pattern. Here's an example of what they look like: How can I use PostGIS to group them ...
1
vote
1answer
28 views

Does the psql prompt have a working directory in the file system?

I am learning postgis. This tutorial says "Navigate to where you downloaded the shapefile." Does that mean navigate to this location in the #psql prompt or navigate to this location with the $propmt? ...
2
votes
0answers
31 views

PostgreSQL : Question about dropping tables inside funtions

I am writing a PostgreSQL code where I have a function wich is used multiple times in a single query with different input values. Inside the function I create some tables and use them. What is the ...
0
votes
2answers
63 views

ST_NumInteriorRings not returns zero, is a bug?

I am using PostGIS v2.0.3, the guide say that ST_NumInteriorRings "will work with both POLYGON and MULTIPOLYGON types but only looks at the first polygon. Return NULL if there is no polygon in the ...
1
vote
1answer
104 views

PostGIS Type Modifier Error

I'm trying to work an example from the "PostGIS Cookbook" and I'm getting an error I don't understand. I'm running the example using Postgres.app on a MacBook. Postgres.app is running PostgreSQL ...