postgis – geoMusings

ToGeoJson and ToWKT for the Esri FGDB API

2012-08-24 by Bill Dollins

In support of some of our ongoing PIM work, we’ve been integrating the Esri File Geodatabase (FGDB) API into some tools. Without going into a level of detail that would hijack this post, one of the many functions performed by some of the tools is to validate physical spatial databases against established data models to analyze compliance and identify differences. These databases may be in Esri or non-Esri formats and we have traditionally handled Esri geodatabases through ArcObjects since it provides a relatively uniform interface across the various flavors of geodatabase.

Of course, ArcObjects requires an ArcGIS license of some sort and we are finding out that this is not always available to users in the field under many situations so the FGDB API gets past that for file geodatabases, at least.

CartoDB/Leaflet Sample Update

2012-07-09 by Bill Dollins

A while back, I posted about some experimentation I did with Leaflet and CartoDB in the wake of FOSS4G in Denver. I recently had the chance to go back and update that sample with some spatial queries. At the time of the original post, CartoDB was still in beta and spatial queries didn’t seem to work, despite the fact that the back-end was driven by PostGIS.

Planet PostGIS Online

2012-07-07 by Bill Dollins

Planet PostGIS, an aggregation of PostGIS-related blog content is now online. As the name suggests, it is built using the same technology as James Fee’s Planet Geospatial but is focused on content related to PostGIS.

If you are working with PostGIS, whether as part of an open-source stack or in conjunction with proprietary tools such as ArcGIS, you may want to check out Planet PostGIS.

Thanks to Regina Obe and everyone involved in setting this up.

Breaking Radio Silence

2012-06-07 by Bill Dollins

Things have been kind of quiet on the blog lately due to things being busy at work. I call that a good problem to have. Since the beginning of the year, I’ve written a a lot of proposals for a mixture of potential customers. Interestingly, I’m seeing a lot more call for “GIS Analyst” work. One trend I’ve noticed, at least in the Federal sector, is that the time between proposal due dates and award announcements seems to be lengthening. That may be an indication of the ongoing flux in funding and organizations try to figure out how to fund their requirements. It will be interesting to see how it shakes out. Of course, it’s good that the opportunities are there in the first place.

One the technical side of things, I’ve been involved in a smattering of things that’s made it hard to roll up one good post. I’m pretty heavily involved in the PIM efforts that my colleague, Barry Schimpf, has been blogging about over on the Zekiah blog.

MapWindow Open-Source Conference Coming Up

2012-05-25 by Bill Dollins

FOSS4G North America

2012-04-12 by Bill Dollins

It’s rather fitting that the second plenary talk on Wednesday had to do with “firehose” applications since the FOSS4G North America (FOSS4GNA) conference was something of a firehose in itself. Despite the fact that the event was smaller than the worldwide event in Denver back in October, I came away with the same “full brain” feeling.

Of course, given the recent production release of PostGIS 2.0, that was kind of the big story for this event. I attended a number of PostGIS/PostgreSQL-related sessions and came away with lots of new information. I especially enjoyed Paul Ramsey’s “what’s new” talk on Wednesday. One thing I enjoy about his talks (here and in Denver) is that he’s not afraid to throw sample SQL up on the screen. It’s one thing to hear about a new feature but it’s another thing entirely to see a concrete example. Some may find the idea of raw SQL in a presentation abhorrent but it worked for me.

A Busy Day for Releases

2012-04-04 by Bill Dollins

Speaking of the 84%…

2012-02-08 by Bill Dollins

HT to Sophia Parafina for the 84%.

UPDATE: The NSIS script at utility batch file discussed here is now on github at https://github.com/geobabbler/pgstandalone. I’ll post a readme in the next day or so.

A few months ago, I asked the following question on Twitter and got this reply from Paul Ramsey:

http://twitter.com/pwramsey/status/136565522836897796

We are working with a Federal Government customer that had the interesting policy that users can install software as long as it makes no changes to the Windows registry. These users are currently running a mix of Windows 7 and XP. We are working with them to help manage one of their data models. In this case, it’s more about performing configuration management on the model/standard itself rather than physical databases with real data in them. It’s a topic we touched on over at the Zekiah blog here and an approach we have used successfully for years to manage the SDSFIE data standard.

PgMap Is Now SpatialKit

2011-10-25 by Bill Dollins

CartoDB + Leaflet = Easy

2011-10-13 by Bill Dollins

One of the biggest sources of buzz at FOSS4G was CartoDB. It is a hosted solution from Vizzuality that uses PostGIS to allow you to store your spatial data online. I got a beta account a couple of weeks ago but life (i.e. paying work) kept getting in the way but I finally got to play with it recently.

One of the things that intrigued me is that, similar to Google Fusion Tables, CartoDB exposes a SQL interface through a RESTful API (I’m still not sure if the term “API” applies to REST but it’s a convenient shorthand). Essentially, CartoDB exposes PostgreSQL SQL and the spatial SQL extensions of PostGIS. Once your data is loaded, you can query it and return the results as either CartoDB’s JSON syntax, KML or GeoJSON.

With this information, I set out to build a simple application to query property data and display the results on a map in a browser. In addition to CartoDB, I elected to use the Leaflet Javascript library to accomplish the mapping (although I also experimented with OpenLayers). Displaying and styling GeoJSON in Leaflet is very straightforward and this task gave me and excuse to get a little more comfortable with it.