Just playing a little today. I’m at Cleveland Give Camp today, working on a project for Ohio City Writers, a non-profit youth creative writing center. I’m deploying some maps for the registration site, that will be filterable, using CartoDB as a host for the data. As I don’t know what we’re going to filter, or where the page will go yet, I was trolling around … Continue reading Using OSM Nominatim to search for geographic objects
The nice thing about setting up something like GeoServer, which is so feature rich, is when you need to pivot based on the demands of a new project, the technical infrastructure is already there, just waiting to be configured or turned on. The case today: feature services. Someone wants to use my existing infrastructure in a new application. I typically serve tile services. One checkbox … Continue reading Serving and filtering #GeoJSON from #GeoServer
In a previous couple of posts (this one, and this one), we dealt with point rotations, first with bounding box searches, and then with nominal use of operators. First we create a function to do our angle calculations, then use select to loop through all the records and do the calculations. Within our function, first we find our first (in this case) five nearest streets … Continue reading Cartography and USGS — Fake Building Footprints in PostGIS now with distance operator (part 2)
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)
In a previous post (I feel like I say that a lot), I wrote about rotating address points to match nearby roads in replicate the effect of USGS quads that represented small buildings with little squares that followed the nearby road alignment. The function was effective: but deadly slow when applied to all 500,000 address points. And so we iterate. First, I’ll show you our … Continue reading Cartography and USGS — Fake Building Footprints in PostGIS now with distance operator
I said it in the title, I’ll say it again, SLDs are not just for ugly maps. I’ve heard from several professionals in this geospatial sector that CartoCSS is so cool– “look at the great cartography you can get out of it”. And, truth be told, creating a standard for cartography that aligns so well with existing web development standards is a brilliant way to … Continue reading Advanced Cartography in #GeoServer– #SLDs can make for very pretty maps
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
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
The feature in PostGIS 2.0 that excited me most was not topology support, raster support, or 3D functions. Ok, raster was near the top of my list. But what I was really excited by was the ST_MakeValid function. Sad, isn’t it? Lack of vision probably– excited to try to solve recurring technical snafus in a computationally inexpensive way, rather than being more excited by the … Continue reading Kicking the tires of PostGIS 2.0 — Testing ST_MakeValid
Quick and fun post tonight. Remember in USGS quads all the little building footprints that represented civilization? We (me and my colleague John Stein) were contemplating how to pull off something similar with address points. Here was our first attempt: It looks ok, but may be a little crude to be considered cartography (click on it to see it bigger– you’ll see those buildings don’t … Continue reading Cartography and USGS — Fake Building Footprints in PostGIS now with distance operator
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