PostGIS is an extension for the PostgreSQL object-relational database that adds support for geographic objects.
0
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1answer
50 views
Creating the node ids：Is this SQL error related to geometry type？
I loaded a multilinestring layer into PostGIS Manager：
and use the SQL query, trying to get the table with the node ids：
ALTER TABLE split_4 ADD COLUMN source integer;
ALTER TABLE split_4 ADD ...
0
votes
1answer
59 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 ...
1
vote
1answer
65 views
From a trajectory of GPS points to a multiline segment
Given a trajectory as a sequence of GPS points I would like to create a smooth linestring representing a path where a car drove. The data is stored in postgresql: the input trajectory in a table, ...
0
votes
1answer
78 views
Aggregate points with same values to polygons
I have a shapefile with 2M measurement points (each measurement point has a resolution of a 1/10). How can I aggregate points around each other if and create polygons out of it?
They do not have to ...
2
votes
0answers
50 views
assign_vertex_id：problems when creating the node ids
Before using pgrouting, I have to create the node ids.
I loaded my polyline layer into PostGIS Manager：
I type this in SQL query：
select assign_vertex_id('split_4', 800, 'geom', 'gid')
But as ...
1
vote
1answer
101 views
Accurate and fast nearest neighbour, which distance function should I use and how to it speed up? [duplicate]
I am solving the following problem:
I have a map with many points in it and I need to find the nearest point to given location. Each point carries information about it's latitude and longitude. This ...
2
votes
4answers
194 views
“Geometry type does not exist” on a Postgis installation on Fedora 18
Just installed PostgreSql and PostGIS over a brand new installation of Fedora 18. I did it this way:
sudo yum install postgresql postgresql-server postgrsql-contrib postgresql-devel pgadmin3
Once ...
1
vote
1answer
42 views
SQL Command to convert pgRouting result to GeoJSON
My goal is to produce a Web UI for pgRouting using this tutorial. I have already imported my data from an OSM pBF to PostGIS using osm2po. Using the pgRoutingLayer plugin for QGIS, I was able to ...
2
votes
1answer
40 views
Force dimensionality with shp2pgsql
After invoking:
shp2pgsql -W "latin1" theshape.shp > thesql.sql
My console responds with:
Shapefile type: PolygonZ
Postgis type: MULTIPOLYGON[2]
Note the shapefile type is PolygonZ. The result ...
0
votes
1answer
38 views
Schema for offline map editing and pass to production environment
I'm working with QuantumGIs and PostgreSQL/Postgis. So when I edit the layers, the changes are reflected on the DB.
The thing is I want to do some "offline" editing before committing the changes to ...
0
votes
0answers
29 views
How to get a session id based map in Geoserver or: best practice to display map in Geoserver from dynamically created Postgis tables
I am trying the following: I have a large table (~2 mill. rows) of the following design
Table "public"."cells_ids_and_counts"
Column | Type
...
2
votes
0answers
48 views
Get Multiple Shortest Path using PgRouting in One Query
I am trying to get multiple shortest path using A* Algorithm available in PgRouting.
I referred Solution given by UnderDark ( Link of the Stakoverflow Post ) . But it is not giving me proper Output.
...
1
vote
1answer
44 views
What is the best way to construct a SQL query that returns the block name for each bus point as it travels?
I have two datasets in postgres; 1) a bunch of points that represent bus locations 2) city block polygons.
Each bus has a unique ID and each block polygon has a field that has the block name in it. ...
0
votes
1answer
69 views
OpenLayers - possible to display detailed GIS data?
I have an OpenLayers app to plot point features, but need to read in a very detailed multipolygon vector layer to plot an accurate location.
I'm currently loading the polygon layer via TinyOWS. I've ...
2
votes
1answer
65 views
Recommended way for changing value in PostGIS using GeoServer
I have a map being rendered from PostGIS using GeoServer. I frequently make some edits to the map and update the new value by directly connecting to the PostGIS database and then making the changes ...
1
vote
1answer
35 views
Difference in raster size using raster2pgsql
I use the PostGIS-build-in raster2pgsql to load SAGA-raster into the db. I tried to grid them into 100x100-tiles, just as seen in the code:
/usr/lib/postgresql/9.2/bin/raster2pgsql -s 32632 -a -F ...
0
votes
1answer
42 views
Shp2pgsql - exec() not allowed on external server
Me and my collegue are using the shp2pgsql and psql commands in php code (a Drupal module to be precise).
We put these commands in a php variable and use the exec() command to execute them. This ...
2
votes
2answers
68 views
merging layer stored in PostGIS
I have a bunch of layers stored in PostGIS that I want to merge. I have spent quite some time investigating various approaches but I ket tripping over getting the GIDs to update properly.
In the end ...
4
votes
2answers
170 views
GeoServer: Shapefile or PostGIS?
I'm going to build a web application, which will render around ten maps using GeoServer. I will be also changing the attribute data in the application for some layers.
So, what is the recommended ...
7
votes
3answers
200 views
Howto setup and use a remote GIS workstation (QGIS,GRASS,PostGIS)?
I'm using QGIS (and sometimes GRASS and PostGIS) on my 2009 MacBookPro for my thesis project.
I was wondering (during an endless batch generalizing in QGIS) if I can set up a server so I can work from ...
4
votes
0answers
71 views
Assigning costs to a road network : use raster or vector?
I have a road network in a PostGis database (db_routing). In another database (db_environment), I have some spatial features of the surrounding environment (trees as points and water bodies as ...
9
votes
1answer
126 views
How to find the buildings (polygons) a user can see from a given location (point) and orientation (angle range)?
I would like to retrieve the set of buildings I can see from a given location (point -lat,lng) and orientation (interval of angles) + certainly with a given depth (e.g. 100 meters). Ideally I would ...
2
votes
0answers
76 views
Extracting x,y,z values from a postgis linestring to python using ogr
I am trying to load a postgis linestring into python (using ST_DumpPoints) and extracting x,y,z coordinates, which is working but extremely slow..and if i mean slow, i really mean it (yes, it takes ...
1
vote
0answers
33 views
Can I use RGeo::Point data in PostGIS queries without multiple conversion?
How can I represent RGeo::Point ( CAPI implementation ) in some way where I don't have to convert it once more in Sql?
Now I have something like this:
class Poly
scope :enclosing ->(geom) do
...
0
votes
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, ...
0
votes
2answers
85 views
Query for Creating a buffer around a particular point
I am working on a project for ambulance management using GIS. using Qgis,Postgresql,Postgis
I am finding it difficult querying using St_dwithin as well as St_buffer.
My aim is to find any hospitals ...
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 ...
2
votes
0answers
68 views
Storing features in PostGIS and then creating layers using queries
I have a whole set of line segments or tracks that represent real tracks or, in some case, boundaries between areas.
These segments form a network of lines on the map.
I have a number of GIS layers, ...
2
votes
2answers
72 views
PostGIS retrieve polygons within a rectangle
I am building a system to bring in shapefile data from a PostGIS database and render it on top of OpenStreetMap tiles using the Leaflet.js library.
My table (sierra_county_parcels) has a polygon ...
1
vote
1answer
40 views
raster tile - find the correct tile for a given coordinate
I have a large raster map which I loaded into postgis with 1000x1000 meter tiles... the corresponding table has about 200 rows, each row representing a tile. I want to get the raster value for a ...
3
votes
1answer
81 views
How to Find points in a Kilometre radius
I am new to PostGIS and GeoData.
I need to find where the lightning has stroke by a period of time and kilometre radius based on a given location.
I have given lon/lat and my table is:
latitude ...
2
votes
1answer
131 views
osm2pgsql Error: operator class “gist_geometry_ops” does not exist for access method “gist”
When using osm2pgsql to import massachusetts-latest.osm.bz2 into PostGIS 2.0.1 database osm (running on PostgreSQL 9.1 on an Ubuntu 12.04), I get the error failed: ERROR: operator class ...
1
vote
0answers
44 views
New geographical point won't show on map
I did recently ask a question about how to add a new point to a PostGIS table. Now when I've got the new point in the table it should be visible on my map, but it isn't.
I'm using Mapnik together ...
7
votes
2answers
177 views
Huge point cloud laser data in PostGIS - Storing and Processing it
I wonder, how it's possible to store huge sets of laser scanned point cloud data in PostGIS, with the time-aspect for processing it in mind. I know, there exists a geometry-object Point in PostGIS. ...
1
vote
2answers
77 views
Get Lon Lat values from a GEOGRAPHY data type in PostGIS
After storing lon lat values as a GEOGRAPHY data type, how do I retrieve the individual lat lon values?
Failed attempt:
SELECT id, geog, ST_X(geog), ST_Y(geog) FROM locations;
Error:
No function ...
0
votes
0answers
19 views
calculating st_simplify tolerance for openlayers
I want to display a vector layer in openlayers. Users can scale the map before they load the vector layer and I'd like to simplify the geometry with st_simplify before sending it to the client.
Does ...
1
vote
1answer
130 views
What format is lat/long stored in OSM PostGIS?
Question:
How do I to get the lat, long for all the toll booths stored in OSM for Virginia?
Current Query:
> gis=# select * from planet_osm_nodes where ('toll_booth' = ANY(tags));
id ...
0
votes
1answer
105 views
Unable to load Shapefile using pgShapeloader / shp2pgsql-gui (pgAdmin3's PostGIS Shapefile Import/Export Tool)
I am trying to load a shapefile (http://dds.cr.usgs.gov/pub/data/nationalatlas/statesp020_nt00032.tar.gz) into PostGIS 2.0.1 using pgAdmin3's PostGIS Shapefile Import/Export Tool.
However its not ...
1
vote
0answers
36 views
Determining the SRID of a dataset in PostGIS [duplicate]
Sometimes the dataset provides some information about its projection. For example, it can mention Horizontal_Datum_Name: North American Datum of 1983, Ellipsoid_Name: GRS1980, ...
0
votes
1answer
78 views
Openlayers Linestring over edge of map
im trying to create a route displayer for ships. But im struggling with the edges of the map. When going from ie. 179* to 2* it displays a line across the entire map, instead of displaying it on the ...
2
votes
1answer
87 views
How to sum values of points inside polygons?
I have a polygon layer of territory and point layer with values from measurements.
I must to add sum values from points layer to polygon layer .
How to do this in PostGIS?
Supplemented:
Point layer ...
0
votes
0answers
12 views
Units of Geometry & Geography data type [duplicate]
When you store data using the Geography data type (like in PostGIS), is it always in lon/lat in degree decimals?
For the Geometry data type, what are the units used in the coordinate pairs? Can it ...
0
votes
1answer
40 views
Finding route contains Source and Destination points
I have a problem with finding routes that are near (in range X km) the passed points (for e.x. A and B) in PostgreSQL PostGIS.
Example:
The point A denotes Source point and The point B denotes the ...
0
votes
1answer
47 views
problems about setting pgrouting with QGIS under windows
I followed this website：A Beginner’s Guide to pgRouting and now facing some problems.
I finished steps before "Creating a routable road network", and open QGIS 1.8, click the PostGIS Manager plugin, ...
0
votes
1answer
87 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?
0
votes
1answer
60 views
How do I get the closest distance for each element within a point coordinate table from a polyline table?
Postgres: How do I get the closest distance for each element within a point coordinate table from a polyline table? And if this is possible what version of Postgres is this doable.
1
vote
2answers
159 views
What Spatial Reference System do I store Google Map's Lat/Lng in
I am new to PostGIS, Spatial Reference Systems and projections and want to store lat/lng coordinates retrieved from Google Maps and Openstreetmap and its services like the Geocoder/Nominatim. I'm ...
0
votes
1answer
98 views
What Spatial Reference System do I store Google Map's Lat/Lng in [duplicate]
I am new to PostGIS, Spatial Reference Systems and projections and want to store lat/lng coordinates retrieved from Google Maps and its services like the Geocoder. I'm working with data in America and ...
1
vote
2answers
55 views
Where can I get public transportation locations for USA
I am trying to find a list of all public transportation/transit locations like subway stations, airports, bus terminals and bus stops for USA. Only major transit locations are required, rural bus ...
1
vote
1answer
62 views
How to perform SIA or Bezier line smoothing in PostGIS?
Can anyone provide an example SQL for smoothing linestrings from postgis table using Bezier curves or Iterative Averaging (SIA) algorithm?
