I am interested on how Zillow.com is able to get the boundaries of a home/lot. I would like to know if this data is open-data and if so, if there was a way I can hook into it? Any and all advice will be greatly appreciated! ...
I want to view and edit some map-like data (obvious things like points / paths / polygons / bitmaps with annotations; also quad-tree masks but I can convert them to something else if needed) in custom format and GIS programs like Qgis seem just fine for right with it. Which formats should I be exporting data into? If possible I'd like t...
Does anyone have a concise and robust implementation of Google's Encoded Polyline Algorithm in C#? I essentially want the implementation of this signature: public string Encode(IEnumerable<Point> points); ...
I am trying to use the ArcGIS 2.1 JS API to create a custom interface that looks similar to Google Maps. What is confusing me (particularly with Dojo's layout scheme) is how Google Maps has a map pane that extends the whole width of the page and has a left search results panel that seems to be floating above the map pane. How does this...
I'm putting together a small library that consumes Geographic Information System (GIS) data and allows for fast point in feature, point near feature, and line of sight queries. Much of this data will consist of big areal features with enormous numbers of vertices. An R Tree variant might work, though I wonder how those perform on the p...
I'm using a great tool (geoxml3) to load private KML data to my Map. However, if a user creates points, polygon and circle features on my map, how can i allow them to export that to KML? Is there a tool like geoxml3 or do i need to create the xml file manually? ...
I want to organize lots of geoPDF files so they can easily viewed overlayed onto Google Maps and Google Earth. My 1st step, I think, is to convert the geoPDF to a jpg type image which then needs matching lat,long information. Is there python code to parse a geoPDF file to get the projection and image data? A geoPDF2KML tool? ...
How can i retrieve OR calculate the coordinates of the NW or SE corners of a Rectangle? I'm using Google Maps API v3 and I know there is the getBounds() method which returns the NE and SW coordinates of the rectangle. I need all four coordinates because KML 2.2 does not have a rectangle schema spec, it only has the polygon schema and ...
Hi, i have two Lidar las files, one is original let's say with X points. And the other is copy of the first las file but with Y points, where Y is less than X. Now, i wanted to compare how the Digital Elevation Models of these two las files vary... I wanted to get information like RMSE, standard deviation, etc... I would appreciate, if a...
I am in the process of creating a consumer facing location based mobile app that will heavily need GIS support. I have narrowed down the databases to Postgres (PostGIS) and mongodb. I was wondering how someone who has experience with both would rate the geospatial support particularly in the area of: Performance Query expressibility ...
This is more of a challenge question than something I urgently need, so don't spend all day on it guys. I built a dating site (long gone) back in 2000 or so, and one of the challenges was calculating the distance between users so we could present your "matches" within an X mile radius. To just state the problem, given the following dat...
I'm looking for an alternative library for the app engine datastore that will do nearest-n or boxed geo-queries, currently i'm using GeoModel 0.2 and it runs quite slow ( > 1.5s in some cases). Does anyone have any suggestions? Thanks! ...
Hi, I'm working on a location extraction algorithm but haven't achieved anything considerable yet. For example in this sentence Riders on the B and Q lines will get some relief from construction as stations reopen, and a major project will soon begin at the Dyckman Street station. "Dyckman Street" is location information. How we e...
How can I get the distance between two google.maps.LatLng points using the Mars/Moon tileset? Python/Javascript preferred, but any language would do just fine. ...
Hello all.... I have a project with various parts.... One of which is the calculate the area of all the polygons on a map. When I run the query "select st_area(nycpp.the_geom) from nycpp;" I get a list of all the areas. Next, I tried adding the results of the query to the nycpp table with UPDATE nycpp SET area_sizes = (select st_a...
Nicklas, thanks for the answer to my previous question.... Forgive me for my ignorance and for asking what may turn out to be rather simple questions, but databases are not my area of expertise. The select statement that gives me the number of crashes in each percinct: SELECT P.precinct, count(C) FROM nycpp P, nyccrash C WHERE _st_c...
I'm trying to get mouseover to work polygons in google maps api v3. I've tried the answer provided in this post: http://stackoverflow.com/questions/1751710/google-maps-v3-api-mouseover-with-polygons This answer should be working, but it's not for me. Can anyone spot the stick in my spokes? Here is my code: <!DOCTYPE html> <html> <he...