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

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Create a point on a line after a specific distance from startpoint

I'm trying to create a point on a line after 10 meters from the beginning of the line. In postgis it is possible to create a point on a certain fraction of total length of linestring ...
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1answer
72 views

How to create a Network Topology in a shapefile that contains only nodes(geometry points)?

I want to use pgrouting with the shapefile but when I use : alter table network.publictransport add column source integer; alter table network.publictransport add column target integer; select ...
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1answer
43 views

Hardware requirements for one instance Geoserver/PostGIS

What hardware minimun requirements do you recomend for one instance of geoserver and postgis and 20 concurrent users? Vectorial data stored in PostGIS is around 20 MB only. I need the ammount of RAM, ...
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1answer
34 views

Export shapefile From PostGIS

I've a website where I'm giving the functionality of creating and editing line features. I'm using Leaflet-Draw plugin for drawing, PostGIS for storing the data and GeoJSON to display it on map. My ...
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3answers
90 views

ST_MakePoint or ST_PointFromText to generate points

I'm new to postGIS and am having trouble finding an answer to this question. I have loaded UK postcode data (OSGB36, SRID 27700 with eastings and northings fields) into a postGIS database. I now want ...
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1answer
26 views

Why does my query not run since SRID are the same?

I am running this query: SELECT source,ST_AsText(ST_ClosestPoint(roads.geom,ST_GeomFromText('POINT(22.256 39.569)'))) FROM roads ORDER BY ST_Distance(roads.geom,ST_GeomFromText('POINT(22.256 ...
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2answers
70 views

How to visualize pgrouting result?

So I use this query SELECT seq, id1 AS node, id2 AS edge, cost FROM pgr_dijkstra(' SELECT gid AS id, source::integer, ...
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1answer
65 views

QGIS WFS-T not updating data

I have asked for help on this topic a few times, but i'll go one more time; with a bit more info. I am trying to edit a WFS from geoserver (using PostGIS data) within QGIS. This is the request as ...
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1answer
32 views

What does st_hausdorffdistance Actually Compare

Does st_hausdorffdistance just look at discreet points used to construct a line segment or does it compare two line segments as a continuous set of points? Also, the points used to construct my line ...
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0answers
68 views

Converting GPS coordinates points to polylines

I happen to have some GPS coordinates points based on timestamp in a table. My table consists of and id , time_stamp and GPS points as the geometrical data. I want to create a line by joining all ...
2
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0answers
22 views

postgres repojection: best practice

I have a postgres/postgis database. I would like to reproject those data coming to me in 4326 to 32736. For those tables with lat long info in wgs84 (4326) I have set the geom to 4326. Then I have ...
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1answer
21 views

Error while make Build osm2pgrouting on openSUSE 13.2

i am getting the error while make /usr/lib64/gcc/x86_64-suse-linux/4.8/../../../../x86_64-suse-linux/bin/ld: cannot find -lpq collect2: error: ld returned 1 exit status make[2]: *** [osm2pgrouting] ...
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1answer
15 views

How to join LINESTRINGS in a specific order in PostGIS?

I have a path from point A to point B, which I want to double back on itself to create a path from A to B back to A. It seemed like using ST_LineMerge on the MULTILINESTRING created by ST_Collect ...
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1answer
43 views

Import KML to PostGIS

I am looking for a way to import my data from KML (example below) to PostGIS database. <?xml version="1.0" encoding="UTF-8"?> <kml xmlns="http://www.opengis.net/kml/2.2" ...
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1answer
42 views

How to use st_touches to get all nearby states

I have a table with all US states geometrical data: USstate ------- state | The_geom (here filling in random value) AL | 00012312 NM | 000234234 NJ | 0000234534 NY | 00005465 ...
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1answer
54 views

How do you combine multiple spatial functions in one query?

I want to find out the intersection and difference in the same query using postgresql. How can I combine both st_intersect and st_Difference in same query and return the result.I want to compute the ...
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0answers
25 views

TileStache some vector tiles failing / postgis connection error

I have TileStache running fine with NGINX/uWSGI on my server. Problems start when I try to render data as vector tiles from a postgis datasource. A few tiles will normally work fine, but at some ...
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0answers
28 views

Capturing points slightly out at sea

I have two tables one containing points (points) and the other polygons (polygons). I want to generate a two-columns table identifying for each point of the first table the polygon containing it. So ...
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1answer
65 views

Conversion of EPSG:3857 coordinate to UTM

I'm trying to convert coordinates from Google Maps using the PostGIS. I'm using this query: SELECT ST_AsText(ST_Transform(ST_GeomFromText('POINT(-29.16297 -51.1795034)', 900913), 29182)); The ...
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1answer
24 views

Merge Point Data and Raster using ST_SetValues in PostGIS

I'm trying to merge a point dataset with a raster dataset using Column X / Row Y. I have written a tool which generates a raster and, from that raster, I have created grid points with ...
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0answers
26 views

Geohash36 for PostGIS

i was wondering if anyone created a ST_GeoHash36 function inside postGIS, i know the ST_GeoHash + ST_GeomFromGeoHash functions exists, But i need the geohash36 function inside postGIS, i need a ...
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1answer
27 views

How to save selected features from a postgis database into a new mini database

I have a postgis(v2.1.3)/postgresql(v9.3) database with geometry (geom1, geom2, etc.) and attribute (attr1, attr2, attr3, etc.) tables. The attribute tables are linked to the geometry tables using ...
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0answers
64 views

Building a ol3 webapplication with dynamic content and user registration

My setup: currently i'm using a postgis database, get it with a geoserver and display it with openlayers 3. I use the wfs data to display the features in clusters and i'm able to edit them with wfs-t. ...
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0answers
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Do you have some reference to create WebGIS? [duplicate]

I need to create a webgis for my thesis. My thesis is create webgis with ms4w and mapfish as framework. I have trouble to show my map. I load map from postgis. So, I need some reference to continue my ...
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62 views

QGIS shapefile layers to database geometry type [closed]

I have opened Arcgis shapefile with QGIS. And I used QGIS database manager tool to create table and import data to postgresql database. Database manager is creating and importing success. But there is ...
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1answer
28 views

Is there a way to configure QGIS to prevent the st_extent call when adding a PostGIS table?

I'm trying to add an extremely large table with a points geometry field to QGIS and QGIS appears to hang. After some investigating in the postgresql database, I tracked it down to a st_extent on ...
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46 views

pgRouting with my bus network and select the best of the available routes? [duplicate]

so here's the case: I have been using postgresql/postgis, openlayers and pgrouting to create an online application that selects and visualizes the best of the availabble routes. My problem is though: ...
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1answer
90 views

How can i use Kriging inside a Postgis database?

i use a postgis database with temperature data. I want to use a spatial interpolation method but not the supported IDW Method. I need to use the kriging Method. Problem is that its no a part of the ...
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39 views

pgRouting 2.0 shortest path with pgr_dijkstra returns an empty result [closed]

I've been trying to automate shortest path finding for a list of points (on pair at a time) using the OSM road layer for Sri Lanka. I'm using pgrRouting 2.0 and have followed the instructions here. ...
3
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1answer
108 views

Postgis is Broken after installing Nominatim

I followed Nominatim Tutorial to install PostGIS and after that I can't access PostGIS at all I already trying reinstalling and installing everything over and over again with no success. Everytime I ...
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1answer
93 views

How to calculate the optimum bus route using pgrouting?

My setup for my web page is OpenLayers, Postgresql/postgis and pgrouting. What I do not understand is how I am going to do the routing.I have read many tutorials but I don't understand what my next ...
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0answers
74 views

Inserting coordinates from Google Maps into a Database

My question is pretty basic. I am using Android Google Maps to take the coordinates off a location on the map and I want to insert it into a PostgreSQL database. I know I have to use PostGIS but how ...
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1answer
29 views

Search Points within Buffered Polygon with PostGIS

I have a table of boundaries as polygons and another table of peaks as points. I want to find the points that are within the polygons and the polygons are extended with a buffer. What would be the ...
0
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1answer
35 views

Spatial query to make view

I've got two tables which I want to combine and enrich with each others data. I'm getting stuck on the join part, as this needs to be done via a spatial query. First the table structure: a table with ...
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1answer
112 views

Google Maps Api , PHP, Javascript and Postgresq-Postgis

I'm trying to make a web application, where I take the start/end city from a text box, geocode the city, use the coordinates to query my database in PHP, and return the features to be drawn in the ...
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1answer
33 views

Can't add a postgis layer in tilemill (symbol shown grayed)

I want to add a postgis layer to a tilemill project but the symbol is shown grayed and I can't select it (shown on the picture below). I followed this instructions.
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1answer
59 views

st_startpoint(the_geom) returning empty values

When I upload a shapefile to PostgreSQL using the QGIS tool I can create the routing topology following this tutorial without any problem. But when I use the PostGis Shapefile Import/Export Manager ...
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65 views

Postgis geocoder size and performance

I have installed Postgresql 9.3.5 and Postgis 2.1.2 on a 16Gb Ubuntu 14.04 system. (1) If I load all the states TIGER data, using the scripts provided in Postgis, how big will the database be for the ...
2
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1answer
45 views

How to transform this PostGIS type of projection to EPSG:900913 in OpenLayers?

I have transferred this kind of projection from this type(which I don't what type it is): 010100000054E077E6F8F33640FD87F4DBD7AD4340 to EPSG:900913. I have the points which are in the above format ...
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1answer
28 views

Selecting PostGIS objects out of given distance

I need to select by SQL querry objects that are further than 100m from specific type of road. For selecting object that are in given distance there is ST_DWithin but what to do in this case?
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73 views

From a point find the closest line [duplicate]

I tried to find a LineString from my table road the nearest line to a point I give, but it is return me all the table SELECT gid, ST_Distance(ST_Transform(ST_GeomFromText('POINT(39.240443 ...
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0answers
29 views

Diminishing performance of gdal_polygonize in a python subprocess for GRASS to PostgreSQL

I have written a python script to polygonize GRASS rasters into a PostgreSQL database using the gdal utility gdal_polygonize: sub.call('gdal_polygonize.py -8 gdb/quercus/{0}/cellhd/{1} -f ...
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0answers
55 views

How to import NetCDF to PostGIS (or GeoTIFF)

I was wondering if there are some online examples/instructions for importing NetCDF files into PostGIS raster images? I looked around, and found this related GIS SE question. However, the answer only ...
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Read and Write data with Open Layers3

I'am currently using postGIS/geoDjango/OL3 I need the capability for a user to drop a point on the map, and store that in my database. When any user returns, that point will be shown on the map. ...
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2answers
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How can I measure(length) line of segment in postgis?

This is my first question. I wonder that, how can I get length of line's segment? Yellow line is my road. blue Points are my start and end points. So I want to measure point1 and point2 between ...
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33 views

Replace for Tilecache?

I tried to use Tilecache with my mapserver/openlayers/postgis/cygwin configuration, but no success so far, I just got tired of keeping digging in the whole system to get that thing working. So, could ...
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0answers
40 views

How to fix scaling mismatch of shape file layer & PostGIS table Lat/Lon data layer for India Map in Geoserver?

I have generated India map in Geoserver using the shape files downloaded from "www.diva-gis.org/gdata" site. Now, when I expose my PostGIS table layer having Lat/Lon data for Indian cities, on top the ...
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1answer
105 views

What controls the direction of TopoGeometry Linestrings?

In PostGIS, what if anything controls the direction that topogeometry LINESTRINGs will have when converted to geometry? It doesn't appear to be the order in which the edges are listed in the call to ...
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45 views

What does it mean when I get rows executed, but with no resulted table?

While applying the following tutorial: http://anitagraser.com/2011/02/09/creating-catchment-areas-with-pgrouting-and-qgis/ utilizing vector network which has been tested (and demonstrated ...
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Why pgRouting GUI panel may not work in QGIS?

What could be the reason behind the mal-functionality of the pgRouting Layer GUI panel? In order to route shortest path via dijkstra function code I'm able to conduct the task using the following ...