Tag: SQL

Analysis, Database, PostGIS, PostgreSQL, QGIS, SQL, TileStache

Plugin-free QGIS TMS tiles via GDAL

Want to load your favorite tiles into QGIS? How about a plugin-free QGIS TMS tiles via GDAL: http://www.3liz.com/blog/rldhont/index.php?post/2012/07/17/OpenStreetMap-Tiles-in-QGIS Really awesome… . Needs but one change: epsg:900913 should be epsg:3857 or QGIS (GDAL?) throws an error. Presumably you could also define epsg:900913 in some config file, but barring that create an XML file as follows, and load as a raster in QGIS: Now I can use … Continue reading Plugin-free QGIS TMS tiles via GDAL

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Analysis, Database, PostGIS, PostgreSQL, SQL

Cleaning animal tracking data — throwing away extra points

Much the problem of the modern era– too much data, uneven data, and yet, should we keep it all? Here’s the problem space: attach GPS collar to a coyote, send that data home, and you have a recipe for gleaning a lot of information about the movement of that animal across the landscape. In order to maximize the data collected while also maximizing the battery … Continue reading Cleaning animal tracking data — throwing away extra points

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3D, Database, PostGIS, PostgreSQL, SFCGAL, SQL

More cutting room floor stuff… — 3D pyramid maker

A little more leftover code from the PostGIS Cookbook— a little tool for making pyramids for SFCGAL enabled PostGIS databases. https://github.com/smathermather/postgis-etc/blob/master/3D/pyramidMaker.sql Edit:  Actually, I think this would work without SFCGAL, but what would be the point… . Edit 2:  Let’s embed some code:   Continue reading More cutting room floor stuff… — 3D pyramid maker

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3D, Database, PostGIS, PostgreSQL, SFCGAL, SQL

More cutting room floor stuff… .

ST_3DIntersection performs volumetric intersections for us in PostGIS, if we have SFCGAL enabled for our PostGIS back end.  Much like a normal PostGIS intersection, this is the mathematical definition of an interesection, so it returns the volumetric portion of the intersection, plus 3D linestrings and 3D points and other bits and pieces that qualify for the intersection.  As a little patch, I wrote a quick … Continue reading More cutting room floor stuff… .

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Analysis, ArcGIS, Database, PostGIS, PostgreSQL, SQL

Proper (ab)use of a database, contour interpolation using #postgresql #postgis #arcgis

Anyone who has been following along at home knows I don’t think much like a DBA.  Sometimes that’s good; mostly it’s probably bad.  In this post, I hope it will be interesting. The problem of the day is how to take engineering contours derived from breaklines, a lidar point cloud, and all the lot, and do a good job interpolating that to a DEM.  This … Continue reading Proper (ab)use of a database, contour interpolation using #postgresql #postgis #arcgis

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Analysis, Cartography, Database, PostGIS, PostgreSQL, SQL, Trail Curation, Trails

Going deeper into web cartography: future=past? (and Swiss cartographic genius)

My favorite cartography book is Eduard Imhof’s Cartographic Relief Presentation.  A few years back I picked this book up (translated to English) from ESRI press for $75 if memory serves me.  Now it can be gotten for much cheaper. Imhof spends a lot of time on feature simplification and separation, a problem which keeps me up at night.  For example, if you have a lot … Continue reading Going deeper into web cartography: future=past? (and Swiss cartographic genius)

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Database, PostGIS, PostgreSQL, SQL

PostGIS for Dessert: Sketching shapes in #PostGIS– compass roses revisited

For one of our applications, we need 8-point compass roses placed at each of our points, as well as a circle 40 meters in diameter as well as one 140 meters in diameter.  We did a bit of work with this a while back in GeoServer using SLDs.  Now we’d like to refine it, and implementing this in an SLD is beyond my skills. So, … Continue reading PostGIS for Dessert: Sketching shapes in #PostGIS– compass roses revisited

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Database, GeoExt, GeoExt, GeoServer, MapFish, PostGIS, PostgreSQL, SQL

Building simple clients for MapFish — cURL as a client

I have two previous posts on using MapFish (in this case, the GeoServer version) to allow for printing to hi-resolution PDF maps from the browser.  Here we use a command-line browser (cURL) to post our json to the MapFish service in order to retrieve our PDF. I did not keep any notes from before on making json posts to the MapFish server as a means … Continue reading Building simple clients for MapFish — cURL as a client

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