Parks Data Cake, part deux

Following up on my previous post, I have started to detail the how of our parks map rendering works, including a GitHub repository with all the code and data to build your own in TileStache. One of these days, we’ll port this to TileMill, but in the mean time, it works and works wonderfully.   — Addendum — Truth in advertising– the contours data were … Continue reading Parks Data Cake, part deux

Parks Data Cake

Stamen has a great blog entry on mapping for parks on their blog. It’s a teaser for a deeper dive in mapping parks, and I’m staying tuned, as their write-ups tend to be detailed, thoughtful, and complete. I thought I’d offer my own teaser– a bit of work done collaboratively with GreenInfo Network.  It started with their basemap– something they spent a few person-years refining from … Continue reading Parks Data Cake

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)

Playing with new tools and old standards: GeoJSON, Leaflet, CartoDB across platforms

Leaflet, CartoDB, GeoJSON, and cross platform web map deployment. First some introductions: “Leaflet is a modern, lightweight open-source JavaScript library for interactive maps for desktop and mobile web browsers, developed by CloudMade to form the core of its next generation JavaScript API. Weighting just about 21kb of gzipped JS code, it still has all the features you will ever need for you web mapping needs … Continue reading Playing with new tools and old standards: GeoJSON, Leaflet, CartoDB across platforms

PostGIS Cartographic Effects– Cartoonify Nearly Coincident Lines

In my previous post, a long 24-hours ago, I proposed some automatic modification of line for cartographic reasons. I had some flaws in my code. The points were over-rotated by 45 degrees. Can you spot why? Tip: it’s a basic trigonometric mistake. Here’s the corrected code (though there may be a better way): An alternate approach is to only move those points that are too … Continue reading PostGIS Cartographic Effects– Cartoonify Nearly Coincident Lines

PostGIS Cartographic Effects– Cartoonify Nearly Coincident Lines

I’m still working on this query, but I thought I’d post what I’ve done so far. My intent is to produce scale-dependent exaggeration of the distances between quasi-parallel lines. The reason for this is so that lines such as street lines which are nearly coincident at a particular viewing scale can be spread from each other, much in the same way great cartography lies a … Continue reading PostGIS Cartographic Effects– Cartoonify Nearly Coincident Lines

Looping Trails– alternate routing for recreational use (cont.)

I’ve been thinking more about the recreational looping problem, given a start location and a given range of travel (e.g. 0-3 miles). A way to approach this is to build up loops from a set of nodes to which has been applied a traveling salesman algorithm. To test this on a piece of paper, before digging under the hood of e.g. pgRouting or OpenTripPlanner, I … Continue reading Looping Trails– alternate routing for recreational use (cont.)

Looping Trails– alternate routing for recreational use

This post will be a conceptual one, rather than technology specific. Imagine a scenario where you want to provide a curated trail experience from a mobile device. You want people to be able to go to a park, pick a starting location (such as their current location) in their device, and query the system for all the possible 1-3 mile loops from that location. How … Continue reading Looping Trails– alternate routing for recreational use