3
votes
0answers
61 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 ...
2
votes
1answer
55 views

Cache geodjango query with bounding box filter

Im using geodjango (postgis) to retrieve points contained inside a bounding box (made by leafletjs), it works so nice, but now I want to cache this query. A tipical query is one like this: ...
1
vote
1answer
56 views

Reprojecting in postGIS from 900913 to 4326. Wrong coordinates

I'm working with postGIS 2.1 I have a table called 'xacementos' created with the srid: 900913. I took the points coordinates from google maps and I want to convert them to SRID:4326 to show the points ...
1
vote
1answer
133 views

How to improve speed of rendering polygons from Postgis in Leaflet?

I want to improve speed of rendering polygons in my Leaflet map. Polygons are stored in Postgis, and are rendered with select query with bbox. I wonder can I cache somehow those polygons? I read ...
5
votes
2answers
471 views

What is the most common way of displaying geodata from Postgis on Leaflet?

For example, in my database I've some points with geographic coordinates. I want to display them on Leaflet JS layer. Which instruments should I use? Maybe there is some API...
1
vote
2answers
161 views

qgis, simplify parcels to share borders

Is there a QGIS plugin or other method that simplifies parcels to share a common line(border)? I'm pretty sure I read about this some time ago. Couldn't find anything here or elsewhere. I'd like to ...
0
votes
1answer
71 views

Postgis objects inside Leaflet circle

How can I retrieve database objects from postgis database which are contained inside Leaflet circle object? I assume circle is only a point with some radius and not a polygon. I wonder can it be ...
2
votes
1answer
87 views

advice on browsing multiple points with leaflet - query only the points in the viewport

This a very basic question, but I donĀ“t quite know where to start I have a postgis table with aproximately 15.000 points hosted on CartoDB And I'm developing an application that should let the user ...
3
votes
2answers
188 views

Is it possible to check incoming GeoJSON to see if any of the features are identical to existing ones before adding to map?

I am working on a Rails/PostGIS app and doing a typical ajax call to retrieve GeoJSON within the map viewport bounds. Whenever the map is shifted or zoomed all of the markers are removed and then ...
2
votes
3answers
707 views

How to add a polygon from PostGIS ST_AsGeoJSON into Leaflet?

I try to use the following function to add polygons to my Leaflet map. function polygon(geojson) { alert(geojson); // alert for testing layer = L.geoJson(geojson); layer.addTo(map); } ...
2
votes
2answers
225 views

Can Geoserver return the raster value of a lat/lon point

I have a GeoTIFF published by Geoserver 2.2 and being used by Leaflet via WMS. How can I get Geoserver to return the raster value at a lat/long point? I'm guessing it has to do with using WCS, but ...
1
vote
0answers
107 views

Creating polygons for a choropleth map using PostGIS

I have a grid of points, each with a value to it as shown in the image below. The data was retrieved from PostGIS and rendered in Quantum GIS. The final result should be a polygons of a choropleth map ...
2
votes
1answer
134 views

Value at a particular spot on Geoserver Heatmap

Geoserver is drawing from a PostGIS database to generate a heatmap using this SLD extension. Leaflet then overlays the heatmap over the base layer. Question: How can you determine the value at a ...
8
votes
1answer
661 views

Generating Heatmap from PostGIS

I have GIS data in a PostGIS data base and would like to generate a density map and display them on a Leaflet/Google Maps. Question: What is the recommended/typical method for doing so, without ...
1
vote
1answer
269 views

Is it possible to use Leaflet, PostGIS and PGRouting for web mapping?

I am newbie at Open Source GIS. I have already create a web mapping using custom tiles and leaflet. I have used my my own database. Tilemill was used to create the tiles and leaflet was used to ...
1
vote
2answers
261 views

Polygon intersection with bounding box with polygon's holes intact

I am trying to serve GeoJSON FeatureCollection tiles with each feature's geometries trimmed to the tile boundary. I am working on a Leaflet plugin to re-assemble the geometries. It works by building ...
2
votes
1answer
423 views

formatting geojson from postgis data using node.js

I am trying to build a GeoJSON object from a SQL query to some GIS point data in a postgis postgresql database. A snippet of my node.js app.js is below. As it stands I understand building the type ...
2
votes
2answers
301 views

How to pull lat/lng from a map canvas and update a database

So if i want to pull out lat/lngs after user clicks on a map canvas (lat/lngs are pulled using any javascript API (leaflet, wax etc.) and add this to a postgresql database using a query, how do i do ...
42
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 ...