Start-up scripts in Debian Linux aren’t exactly straight forward for the un-initiated. Actually, if memory serves me, they aren’t any more straight forward on Ubuntu Linux either, but such is heredity. We are transitioning some of our GeoServer instances over to 64-bit Debian Linux. In my test Ubuntu environment, I had a hack in place to force the Tomcat Java Servlet to launch on startup, … Continue reading Debian Configuration– Tomcat on Boot
I don’t spend much time on field equipment, e.g. GPS units. Why? Lack of interest? No. Lack of space in my job description. Yes, I know. A GIS Manager who doesn’t have a GPS is it’s own category of silly. None-the-less, when a colleague told me that Garmin now has firmware support for custom maps for some of it’s GPS units, I told him it … Continue reading Garmin Custom Maps
The stats helper monkeys at WordPress.com mulled over how this blog did in 2010, and here’s a high level summary of its overall blog health: The Blog-Health-o-Meter™ reads Fresher than ever. Crunchy numbers A Boeing 747-400 passenger jet can hold 416 passengers. This blog was viewed about 6,100 times in 2010. That’s about 15 full 747s. In 2010, there were 29 new posts, growing … Continue reading 2010 in review– Easy Squeezy Blog post (since I didn’t write it).
I’ve said before that I work in a hybrid shop– part ESRI, part Open Source. We use GeoExt/OpenLayers/GeoServer/PostGIS for the Enterprise stuff, and ESRI for the analyses, some specialized cartography, and the easy way out on one-off projects. I mostly blog about the Open Source stuff, ’cause that’s where my heart (and budget) lays. So, now for some ESRI Fan geek-dum. Plus the obligatory work … Continue reading ArcGIS, Layer Packages and Workarounds
SELECT b.gid AS gid,
ST_Closestpoint(ST_Collect(a.the_geom), b.the_geom) AS the_geom,
b.stream_nam
FROM public.hydro_polyline_merge1 a INNER JOIN base.streams_phwh b
ON ST_Dwithin(a.the_geom, b.the_geom, 1000)
GROUP BY b.gid, b.the_geom, b.stream_nam Continue reading SQL/MMore Acrobatics
Another short post… . I have in place a framework for maintenance of our boundary data that works really well. I feed an edited shapefile into the database, and PostGIS creates all the versions of the boundary that need created. The database then exports the managed data to shapefile so there is a database version and a shapefile version depending on need. When all was … Continue reading Shapfile spatial indices and PostGIS dumps
This will be one of my shorter posts. pgadmin III allows for the development of scheduled tasks that run on your PostgreSQL database. As my PostGIS triggers have gotten more complicated, and since they run per transaction to keep ACID compliance, a big mess can be made by just updating a dataset (this is what vacuum is good for), and the time for inserts can … Continue reading pgagent — when triggers are too much
I maintain a lot of versions of our exterior property boundary layer for our park system for different purposes, e.g. this post. What I’d like to include in this automatically managed dataset is a multi-ring buffer version of the dataset for the purpose of a careful mask with fade (also useful for showing coastal vignettes— oops, ESRI link), e.g.: So, first we buffer: And discover … Continue reading Multi-ring buffers in PostGIS
Very simple post today, mostly so I don’t forget, but R is an open source statistical package that is amazing. Eventually I’d like to integrated it with PostGIS for analyses. In the meantime, I stare off dreamily at other people’s posts on R, e.g.: http://casoilresource.lawr.ucdavis.edu/drupal/blog/2 Continue reading Arrrh! Well, R anyway
A quick review of costs to search with increasing distances. Reference this original post for the code being run. SELECT DISTINCT ON(g1.gid) g1.gid as gid, g2.gid as gid_ground, g1.x as x, g1.y as y, g2.z as z, g1.z – g2.z as height, g1.the_geom as geometry FROM veg As g1, ground As g2 WHERE g1.gid <> g2.gid AND ST_DWithin(g1.the_geom, g2.the_geom, 3.5) ORDER BY g1.gid, … Continue reading Cost of nearest neighbor search depending on distance
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