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

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How to reconstruct a network with multipart edges to a network with singlepart edges

I have a network shapefile that between its vertices , there are edges that have multiple geometric objects. When I try to node it in postgis, it creates multiple segments in the database that ...
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29 views

Use of constraints and Spatial indexes in Postgis

We'are using Postgis to manage our geo data. They are coming from several sources, like Open street map, VPF, Shape and so on. We have defined constraints on the tables, and spatial indexes on ...
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63 views

Snapping feature nodes doesn't work after feature creation (filter involved)

I've experienced a strange behaviour during editing mode: I have set a filter to 2 features (polygons), part of on of my PostGIS layers: "name"='A' OR "name"='B' After that I have created a new ...
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32 views

Postgis - create function for verify position of a point

I have 2 tables that are more or less like this CREATE TABLE localizzazione.etichette_sentieri ( gid serial PRIMARY KEY, cod_grid character varying(10) NOT NULL, geom geometry(Point,32632), ...
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134 views

Reprojecting in Postgis

I try to reproject a layer in PosGIS using statement: UPDATE <table> SET geom=ST_Transform(geom, 3857); leading to error message: ERROR: transform: couldn't project point (574415 6.22508e+006 ...
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Error in osm.xml while generating the output xml for tile server using generate_xml.py

I'm setting up my own tile server using PostGreSQL, PostGIS extension, mapnik and osm2pgsql. While trying to generate the xml by using the command: E:\>python generate_xml.py download_osm.xml ...
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55 views

Calculating slope from elevation returns hole when using ST_Slope in PostGIS

I have rasters from the National Elevation Dataset loaded into a PostGRES database and am using the built-in function ST_Slope to calculate the slope. However these contain many holes where there is ...
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68 views

MultiPatch Shapefile import into PostGIS Database

I have geometry of buildings in Shapefile MultiPatch format. I want to import it into PostGIS database in the same format. Is that even possible? If yes, then how?
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30 views

How to specify the new layer type in writeOGR{rgdal}?

There is a task that we copy some polygons into postgis using rgdal package. I noticed postgis is strict with geometry type so that the new multi-feature layer type must be specified. I tested the ...
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87 views

H2GIS and POSTGIS

i use PostGIS and H2GIS and i have tested ST_Transform function on both systems: SELECT ST_AsText( ST_Transform( ST_GeomFromText('POINT('||to_char(5873455.6,'9999999.99')||' ...
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60 views

Converting NAD 83 to WGS 84 in PostGIS

My question is about the best way to convert from NAD 83 to WGS 84 in PostGIS. I have a PostGIS DB containing National Elevation Data rasters. The rasters are in NAD 83 and I would like to convert ...
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100 views

How to relate a Spatial and Non Spatial table in PostGIS to be visualized in QGIS

first of all I'm quiet new in PostGIS. I'm working in pgadminIII with postGIS. I have in one database two tables. See the two tables SQL Pane. CREATE TABLE gw_body_characterisation2 ( ...
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152 views

How to convert a geojson from Postgresql to geojson format readable in rCharts in R?

I am creating a Rshiny interface on that can take in user input and SELECT the respectively map layer from Postgresql database based on the input. The package I am using to plot the map is rCharts. ...
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68 views

In PostGIS, is it possible to use `ST_SnapToGrid` align to a coordinate system?

I am wondering if it is possible to align a raster or geometry by specifying the coordinate system using the spatial reference identifier, i.e. 4326 for WGS 84. I did not see anything in the ...
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22 views

How to remove lines made with a PostGIS query automatically if origin is not in the map window?

I have a PostGIS point layer with labels. I moved these points because they were too close. To connect label and point, I created a line vector layer which was made with a query in the DB-Manager ...
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55 views

Windshaft + Postgres to read geojson

I am using Windshaft and trying to figure out how I can take a geojson text object from Postgres and have it rendered as a tile layer. I have tried the following query: sql: "select ...
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44 views

Up-dating postgis spatial table from CSV files

I have a PostGIS Table I produced from importing a layer file itself created from a CSV. I am getting updates to the main file through other CSV files and need a method of importing the new CSV's into ...
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70 views

Web Application for display raster data on basis of time slider

It May act as a duplicate question to many, but i have tried refering too all the questions related to my questions, but i am still confiused. Below in attached my code. which i use for Web Mapping ...
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34 views

Unable to Display Postgis Database Table Geometry Column Points in Geomoose

I'm a beginner in this field.I want to plot the postgis database table geometry column in geomoose but it is showing a pink tile.Through an android device we are pushing latitude and longitude to ...
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44 views

Densifying OpenStreetMap (OSM) network nodes?

I am working with osmconverter to convert osm files(*.osm) to *.pbf, then i use osm2po to get sql file that run into PostGis to get a network table. The last step is to run a createTopology ...
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26 views

polygonize some raster pixels based on their value in PostGIS

I need to extract and polygonize only those pixels of a raster that have a value (e.g.) greather than 2000.0 The reason is that I wish to do an operation like the following one (which is done only on ...
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87 views

Use QGIS and Qt dialog forms

I have a QGIS project where there are plots with a attributes like name of the owner, address of the owner, cultivate, and so on. This plots are read from a PostGIS database. The future users of this ...
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204 views

OL3 doesn't display the wms Layer

This is pretty much related to the question asked in the following link How to add Mapserver WMS to Openlayers 3 I followed the example in ...
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42 views

How to arrange polygon in Postgis

I have a lot of polygons in a Postgres database. I want to show the polygons, but in order of the the biggest to the smallest. I used the following code: SELECT ST_Area(area_polygon) as luas FROM ...
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65 views

Speeding up PostGIS ST_AsGeoJSON

I am writing a query that would give me the geojson element contains the outline of a US State along with some additional information. The problem I am running into is the function ST_AsGeoJSON from ...
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86 views

How to use a PostGIS sequence in QGIS editing session?

I can't seem to get the sequence on my PostGIS table to increment to NEXTVAL in a QGIS editing session. My PostGIS table is defined as: CREATE TABLE qgis_topology_editing_test ( geom ...
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25 views

Display graduated QGIS buggy?

I counted points in polygons in PostGIS like this UPDATE hexagons SET count = (SELECT count(*) FROM points WHERE ST_Within(points.geom, hexagons.geom)); That came back with that UPDATE 1554 That ...
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84 views

load raster (geotiff files) to postgis with url

I tried to load rasters to postgis with raster2pgsql but this not satisfy my project because it uses local files. i have 5000 and will be more in future geotiff files in cloud host. is it possible ...
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62 views

Method to translate PgRouting to ESRI Network Analyst network dataset?

I have a network dataset in a PostGIS database that is set up and routable via PgRouting. I would like to take this dataset and import it into Network Analyst in ArcMap in order to make some ...
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40 views

Cannot draw geometery on WorldWind

I'm trying to draw my geometery on worldwind but it keeps saying WARNING: Unspecified coordinate system and draws a default blue line in the middle of nowhere. The procedure is that I populate ...
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23 views

Need to find polygon info from postgis

After importing shapefile into postgis I got geom data as MultiPoligon Like: ...
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47 views

Getting connected points in intersection from OpenStreetMap using PostGIS?

I'm trying to get the points that connected with the intersections. suppose that I know the point of the intersection (if we see in the pictures, I represent the intersections as black node). Now ...
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94 views

Splitting lines table using point table in PostGIS

My problem is that I want to get the shortest route between multiple point pairs which are stored in a table (PostGIS). In PostGIS I also have a network created using pgr_createTopology on a table ...
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90 views

Can't create ArcGIS feature class with PG_GEOMETRY keyword

I have enabled a PostgreSQL database as an enterprise geodatabase with ArcCatalog 10.3 (using server license file etc). When I create a new feature class with PG_GEOMETRY keyword, I get an error: ...
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49 views

pgRouting pgr_trsp returns no route

Installed a fresh PostgreSQL v9.4.1 x64 on Windows, and used the Application Stack Builder to install PostGIS 2.1 bundle which includes pgRouting 2.0. I created the sample data ...
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38 views

Determining intersection between list of points and list of linestrings?

I'm coding in php. I have a list of point coordinates (very large one) and a list of linestring geometries (large too). I'd like to determine for each linestring, the point coordinates that ...
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56 views

KNN combined with other clauses

I have a table with columns:- wkb_geometry (geometry), road_id character varying, year INTEGER The data set has multiples of road_id across many years. I want to get the nearest 10 values to a ...
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59 views

Tilestache - Mismatch between the coordinates present in the PostgreSQL/PostGIS and those returned by PostGeoJSON provider

This is the relevant bit my Tilestache config, "points-of-interest": { "provider": { "class": "TileStache.Goodies.Providers.PostGeoJSON.Provider", "kwargs": { "dsn": ...
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35 views

How to share constraints between tables in a PostGIS database?

I have a PostGIS (v2.1) database that contains several tables, each representing a raster that I loaded by calling raster2pgsql. I'd like to ensure that the rasters contained by these tables have the ...
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67 views

Raising height of a certain part of choropleth

I have a working choropleth map which shows number of patients in a certain coloured area. I want to raise the height of the specific area according to the patient count. The variable height is equal ...
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81 views

Perfom SQL queries in Python and process the result

I query column names from a PostGIS table with following Python code: colnames = [] sql_getcolumns = "select column_name from information_schema.columns where table_name='shp2py';" ...
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24 views

Branching factor in River system?

I would like to find the branching factor for a river system. I have tried dissolving it then trying to find the branching factor but I'm not to sure how. So I have it from west to east like it ...
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75 views

PostGis - ST_AsRaster returning raster smaller than reference raster

I am trying to convert a point geometry to a raster using a reference raster: SELECT ST_AsRaster(my_points, ref_raster) FROM my_table This works fine except it is only returning a subset of the ...
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89 views

WMS problems Qgis server with postgis

I have installed qgis and qgis server on a windows server. My plan is to use qgis server to generate a wms. It works fine when I'm using shape files in my qgis project, but when I'm adding a postgis ...
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65 views

Find hotspot with highest density for two objects

I'm using PostgreSQL/PostGIS and I have an advanced type of query. My database contains two types of objects - let's say homes and crime. Is there a way that I can find the area with the densest ...
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67 views

pgsql2shp query error select

I need to export from postgis some data obtaining the center of my polygons, now I'm working on Ubuntu. My command looks like this: ./pgsql2shp -f /home/me/ESTADOS_POINT -h localhost -p 5432 -P ...
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34 views

Extract table-embedded attributes in KML using ogr2ogr

I'm loading a number of diverse data files into a PostGIS database, using ogr2ogr. One of these data files is a KML with useful attributes embedded as an HTML table in a description column: ...
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141 views

Implement Leaflet search box for 370,000 points stored in PostGIS served as raster tiles

I have built http://opentrees.org. It's a TileMill/PostGIS/Leaflet stack with raster tiles and UTFGrid interactivity. I'd like to add a search box, so users can search for a feature – trees in this ...
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268 views

ST_MakePoint returns an error when using Python

I am trying to use ST_Point or ST_MakePoint to create points from a table of latitude and longitudes coordinates. However I am consistently getting an error even when trying the examples. For example ...
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133 views

Create a route by using points (pgRouting)

I'm currently working on a routing model for 17th and 18th century voyages. These routes are based on data from old shipping logbooks. I made a separate layer in QGIS which contains point. I exported ...