0
votes
1answer
37 views

40k+ points from Shapefile, clustering them and populating on Google Maps/Webapp

I just started a new Python/Django webapp job related to GIS (and i'm totally new to GIS). Here is my task and what i have found so far, and i am stuck as to finding out what's the best way or the ...
0
votes
2answers
83 views

Python library or algorithm to generate arc geometry from three coordinate pairs?

I'm trying to write code to generate fixtures for a django/geodjango project. I need to generate geometry for arcs (line string) given three lat/long pairs; start of arc, end of arc and centre of arc. ...
1
vote
1answer
37 views

Can't get SRS from PostGIS using Proj4 text

I'm having a problem transforming a point from the Australian MGA UTM datum (eg MGA Zone 51 http://spatialreference.org/ref/epsg/28351/) to WGS84 using GeoDjango. I've narrowed that down to a problem ...
1
vote
1answer
104 views

Geodjango read raster files

I am developing a web app in geodjango (django) framework but I need to import raster files. Is it possible a geodjango app read raster files from a directory? Thanks
1
vote
1answer
43 views

GeoDjango Scale/Layers issue?

I've been having issues visualising data from a shapefile in GeoDjango using OpenStreetMaps. I believe it's some sort of a scale issue because of how it appears(as you can see in the screenshot of the ...
2
votes
1answer
155 views

GeoDjango - return SRID of geometry in GeoQuerySet

I'm wondering if there is a function in GeoDjango which would allow me to determine the SRID of a geometry column in a GeoQuerySet. I know I could do it with a raw SQL query (I'm using PostGIS) but I ...
9
votes
4answers
505 views

How to use PostGIS to handle complex geoprocessing workflows?

Our organization is considering moving our geoprocessing workflow to PostGIS. We are currently using ArcGIS, with a plethora of custom Python tools used in ModelBuilder. We're moving most of our data ...
3
votes
0answers
196 views

Is there a Python WMS client (thin client analogue of OpenLayers)?

I'm making a geoportal based on (Geo)Django 1.5, PostgreSQL 9.1 + PostGIS 2.0, QGIS MapServer and OpenStreet Map or Google Maps WMS services for the base layer. It seems like there is no problem, but ...
0
votes
1answer
84 views

Anyone recognize this (reference-system related?) pattern of distortion?

I'm new to GIS and was making some progress until getting rather stumped on this one. I've imported what I believe to be lat/lon data based on US FIPS county codes in weather alerts (NOAA SPC). When ...
0
votes
1answer
192 views

Save longitude and latitude in Django

I had plotted a Javascript gMap.Using the marker,the values of latitude and longitude are displayed.I need to get that values and save it to database.What is the best way to do this and ,How to ...
7
votes
1answer
1k views

Pros and cons of using Ruby/Rails/RGeo or Python/GeoDjango for a web based GIS

We're at the investigation phase of creating a web based GIS. We're assessing options for an ORM to use in all of our backend import/export and processing routines. From my research, GeoDjango appears ...
0
votes
1answer
93 views

Error on rendering linestring

I am using Mapnik 2.0.1rc0 on a Windows 7 with python 2.7 32bits inside a GeoDjango App using xml. The datasource come from spatialite 4.0. My tiling script can render polygon and point features ...
0
votes
0answers
193 views

mapnik error - fatal flex scanner internal error--end of buffer missed

I am using Mapnik 2.0.1rc0 on a Windows 7 with python 2.7 32bits inside a GeoDjango App. I often got this error: fatal flex scanner internal error--end of buffer missed that makes python to crash ...
1
vote
1answer
89 views

GeoDjango - Use GDAL python binding in the shell

I would like to use the GDAL python binding in my GeoDjango site. The aim of this is to use ogr2ogr capabilities in a script. I am on windows 7 so I have installed GDAL-1.9.2.win32-py2.7 downloaded ...
1
vote
0answers
334 views

Get the distance between 2 WGS84 GEOSGeometries

I currently want to check if 2 given GEOSGeometry objects of type Point are within 100m of each other. (length flexible) Looking at previous asked questions on this topic, most of the answers were ...
3
votes
2answers
460 views

Checking if a point is in a circle

I'm using shapely to check if a point is in a polygon, but I also need to check if a point is in a circle. Checking the docs, I don't see how do that... Maybe I could create a circle? circle = ...
4
votes
4answers
369 views

How to compute geodesic area in GeoDjango?

I have some polygons which can be anywhere in the world. I would like to compute their areas. The GeoDjango docs for GEOSGeometry.area don't specify whether it is geometric or geodesic area, but ...
3
votes
1answer
514 views

GeoDjango Changing My Coordinates

I'm running into a problem when saving a coordinate into one of my models in (Geo)Django. My point field is setup as: location = PointField(blank=True, null = True) So while running some tests in ...
3
votes
2answers
306 views

Invoke PostGIS functions outside of the database? Need to force 3D in GeoDjango

I'm looking to ensure that all geometries saved to the database are three-dimensional. It's easy enough to do with a call to the database, select ST_Force_3D( ST_GeomFromText( blah blah ) ) ...but ...
4
votes
1answer
243 views

geodjango slowness and debugging

I'm using geodjango + postgres to display polygons from tigerline on a map. Pretty simple stuff so far. My issue is that when I use the GPolygon object: django.contrib.gis.maps.google.GPolygon there ...
4
votes
1answer
634 views

Wrap GEOS functionality into python

I've been looking on how to get GEOSExtractLine available in python. I looked into Shapely source to if it was available for it, but it's not. I'm trying to wrap this funcionality into Django, much ...
-1
votes
1answer
123 views

GeoPortal Managing Tool [closed]

i know in this site everybody more or less have been setup a geoportal for showing their basemaps and analysis on local or net for their workers or conserned people in the net. it is obvious that in ...
1
vote
1answer
197 views

GeoDjango 'NoneType' error when using 'distance' function

I have a site that's working on our staging server but after copying it to the live server I am getting the following error when trying to perform a distance() call (code cut down to minimum) ...
2
votes
1answer
1k views

Using a geodjango PointField with geography=True, my distance calculations are wrong

Here's my model: class ExchangeArea(models.Model): """ An Exchange Service Area, calculated from a phone exchange and surrounding census tracts. """ coordinates = ...
7
votes
3answers
966 views

Use Esri Geoservices REST as backend for Python web framework (Django?)

I would like to know if it's feasible to use an existing Python web framework such as Django/GeoDjango as a frontend to work with Esri's Geoservices REST API? I envision developing a database engine ...
3
votes
2answers
507 views

PostGIS + pgRouting: Adding dummy links to a road network and performing routing analysis

I'm a beginner when it comes to postgis and pgrouting development. For a project I'm working on and a bit of the algorithm: I have a polygon layer that represents zones I have a line layer that ...
7
votes
1answer
196 views

Optimize GEOSGeometry's spatial operations by avoiding thread-safety checks

A ranking algorithm I'm developing for a Django webapp requires performing spatial operations (within, intersections, sym_difference, etc.) using a query against large number of geometry objects. ...
2
votes
1answer
750 views

Area units for GEOS area property?

I'm working with GeoDjango and have a polygon in the WGS84 projection. I need to find its area in square meters. When I call polygon.area, I get some float out and I have no idea what the units of ...
6
votes
1answer
381 views

Is there a GeoDjango tutorial for GeoRSSFeeds?

I'm going through GeoDjango basics right now. Ideally, I'd like to publish a GeoRSS from a set of data I have that is already in Django's database. I know how to get a regular Feed working, but when I ...