0
votes
0answers
48 views

How to create a vector layer from a GeoAlchemy2 query?

I'm currently developing a QGIS plugin where I mapped a PostGIS database via GeoAlchemy2. I wrote a function that returns results from a GeoAlchemy query but have no idea how to create a vector ...
0
votes
0answers
37 views

rasterize table polygon postgis 2.1

I would like to rasterize a postgis 2.1 polygon table, but I don't undersand how to create the SQL function syntax for ST_AsRaster. My vector table has 3 fields: gid, recharge, and geom. The SQL ...
2
votes
3answers
132 views

How to get a bbox selection of huge shapefile as GeoJSON?

I have a 4.29 GB Shapefile from which I want to extract features as GeoJSON, defined by a bounding box. This should be as fast as possible, because I want to use it in a web application. My first ...
-1
votes
1answer
585 views

Retrive data from database in openlayer GIS

i am using this code but it shows nothing, whats wrong with this code. <!DOCTYPE html> <html lang='en'> <?php $conn_string = "host=localhost dbname=postgis_21 user=postgres ...
0
votes
1answer
401 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) ...
3
votes
1answer
232 views

Visualizing Spatial Query

I'm new to GIS applications and trying to figure out what options I have for visualizing spatial query results that combine raster and vector data using OpenLayers/GeoExt/GeoServer/PostGIS. A ...
6
votes
1answer
188 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 ...
0
votes
1answer
158 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 ...
3
votes
2answers
4k views

How to connect OpenLayers to PostGIS data?

I have read in OpenLayers how to load KML, GeoJSON etc. vector files in OpenLayers. But how can I connect to PostGIS data. If not, why should I upload my data to PostGIS then instead of directly ...
5
votes
1answer
450 views

Converting polygon values to a vector grid using PostGIS

What is the best way of converting a value from irregularly shaped poylgons to a polygon grid using PostGIS? I have a set of polygons that look like this: and I would like to overlay a grid on ...
3
votes
1answer
145 views

Creating a vector based design from a raster database

I have a raster table that I've created using Postgis raster. It has 365 records and the table looks like this: +-----+------------+---------+------------+ | rid | rast |filename |date_of data| ...
1
vote
0answers
143 views

How to config geoserver to read style of vector layer from postgis/SQL store?

I've imported vector layers from map info pro to both SQL server and post gis using easy loader. In both cases I've included style column in the exported table. When I create new store in geoserver ...
1
vote
0answers
23 views

How do I draw a square on a vector layer from PostGIS? [duplicate]

Possible Duplicate: Is there a tool/plugin/script for QGIS that would allow for manual corrections to vectors and also allows for connection to postGIS? I am trying to draw two squares on a ...
3
votes
3answers
192 views

How can I draw squares in PostGIS layers at different angles?

I am trying to draw two squares on a 45-degree angle and then merge them using PostGIS to edit. QGIS can draw squares but only on a perpendicular plane (eg, 0, 90, 180), and I need to be able to draw ...
5
votes
1answer
205 views

How to cache PostGIS views?

Does anyone knows if there exists a caching system for views or queries in postgis? I have a system that gives information through a webpage using a postgis view as backend. The problem is that, ...
43
votes
8answers
7k views

How to create Vector Polygons at the same amazing speeds GISCloud is able to render them?

EDIT (outlining new bounty added): I have added the largest bounty possible to this question in hope of getting a very detailed answer. Your solution should outline a step-by-step guide utilizing open ...
5
votes
1answer
842 views

How to draw or edit curved lines in free GIS?

I'm searching informations about drawing simple curved arrow lines into free GIS like QGIS, in this problem data geometry is CIRCULARSTRING ( a type which exists in latest postgis version) It seems ...
6
votes
1answer
404 views

How to use simplify()

i have my Vector Data saved in a PostgreSQL PostGIS enabled Database. The Data im displaying is very detailed, i want to simplify it through the simplify() method of Postgis. I duplicated one of my ...
18
votes
7answers
6k views

Nearest neighbor between a point layer and a line layer

I've asked this question several times on stackoverflow and irc between #qgis and #postgis and I also tried to code it or implement it my self in postgis with no real answer. Using programming (most ...