About scales

Published on July 5, 2010 in Random Box. View Comments Tags: , , .

The Metric System is one of the things you’ll start missing most after a transatlantic move. Distances are no longer distances, voluminas and weights are messed up, soccer-fields and hectares don’t mean anything to anybody in this world. Smartphones and little converter apps are the only things that give you some clue about what’s going on.

Now, over a year after my move over the ocean, I still catch myself responding to a “400ft on the left hand side” with a silent “whatever”, and trigger a recalculation-process to the system I’m familiar with. Seriously, given the fact that there is absolutely no easy way to master feet, miles, yards, acres, sq mi, ounces (volumina and weight in one measure, for Christ’s sake!), pounds, pints, cups, gallons, etc. I started asking myself, how did this country even get so far?

The one scale I started appreciating however, is Fahrenheit. In terms of human readability and usability, I think Fahrenheit is a great scale. First you need to know that people refer to temperature here with “it’s going to be in the 60ies”, meaning the temperature will be between 60F to 69F. 9 deegree variation seems a lot if you’re used to Celsius, but it’s not that big of a deal in Fahrenheit. I’ve learned that the term “in the 60ies” gives you very precise information about how to prepare for the temperature. Much more than I’ve ever learned to correctly read the Celsius scale. Let me illustrate this with my personal Fahrenheit scale, that I’ve sort of developed over the last year:

  • everything < 50F: freezing, winter coat weather, below 40F thick winter coat
  • 50ies: cold, don’t leave the house without jacket
  • 60ies: chilly, you might want to bring a light jacket or some long sleeve shirt
  • 70ies: nice warm, t-shirt, maybe shorts, I still prefer long trousers
  • 80ies: hot, clearly shorts conditions
  • > 90F: sweat, don’t forget your water bottle

See?

In Celsius the same information would be much more granular and not as easy to memorize. Usability of Fahrenheit is way superior to Celsius’. Despite the insanity of all the other scales, I really came to like Fahrenheit a lot here.

Boston mapping folks!

Published on May 12, 2010 in Geomensch. View Comments Tags: , , , , .

… join the

Boston OSGeo Enthusiasts Meetup

next Tuesday, May 18th, 6:30-8pm

at the Bocoup Loft (319 A St, Boston, MA 02210)


View Larger Map

… and meet other Open Source mapping software users and developers, share experiences, learn about tools, discuss projects and developments.

To RSVP, please just add your name to the Doodle.

For more information and to participate in planning the meetup, please join the mailing list and follow the May meetup thread.

See you there!

Playing games

Published on May 11, 2010 in Geomensch. View Comments Tags: , , , , , , , , .

Last week has been pretty intense. My department finalized a, for a regional planning agency, rather unusual project and ran a couple of community meetings during the week. What happened in those meetings wasn’t the typical PowerPoint presentation followed by a Q&A. People, mostly of younger age, played a 3D video game and participated that way to Boston’s Chinatown Masterplan process.

Emerson students created the excellent video below, that captures the very core of the project in about 3 minutes:

I only got during the final phase of the project involved, helped testing the game, setting up the website and organizing our community meetings, but it was an absolutely exciting experience to take part in. Especially the first community meeting, hosted for Chinatown residents, stood out with an highly energized atmosphere.

The game helped in the meeting as ice breaker, facilitated engaging discussions about the neighborhood and provided a fun environment for the audience to work with. We all were somehow surprised when we actually saw game mechanics kicking in. At the point where scores and winners are announced, people started cheering, got all excited, compared scores and discussed strategies why one couldn’t complete all tasks or what would have been a better way to play.

The good part: it all had serious, real world backgrounds – well, real world compressed into 30 minute tasks. However, the game deals with existing challenges of Chinatown residents. The game allows players to walk in somebody else’s shoes through Chinatown and complete tasks as another person, equipped with different skills and opportunities. It’s an educational game, used to gather feedback on and engage in an urban planning processes.

But it’s still fun to play, and fun is the one aspect I wouldn’t underestimate here. It helps to broaden the audience of the community meeting, attracts especially younger people and provides an experience you wouldn’t expect.

Although the game can be played online, it is designed for meetings, to be played by people located in the same room. The game serves as facilitator for participation and gets people talking to each other, very actively as we found out during the meeting. The game is not designed as standalone solution.

The online game version should extend the dialog started during the meeting and provide opportunities for others to chime in at any point (we’re working on it, almost there).

Further readings:

Bike with Google

Published on March 10, 2010 in Geomensch. Closed Tags: , , , .

It’s all over the (map/bike) news: Google added the long anticipated Bicycling layer to Google Maps, which shows bicycle facilities and enables bicycle directions. Excellent!

It’s a great move for bicycle advocacy and helps increasing awareness about cycling as serious urban transportation mode. According to that blog post on the Google Lat Long Blog, the Google Maps engineers developed some solid bicycle routing algorithms. The data is apparently coming from Rails-to-Trails, public sources and Google’s Street View and Imagery. In the areas I viewed, all data was (c) Google, which is, after we saw the parcel layer (c) by Google, not surprising at all.

Nice side effect: bicycling is available in Google Maps API V3 (which recently made it into OpenLayers).

Even though the bicycle layer looks pretty impressive at a first glance – lot’s of green lines in the Boston area – it’s clearly in beta stage. For my daily commute it suggested three basically realistic alternatives, only with 1 to 3 blocks detours from the route I usually take. My usual route includes going up a quiet one-way street which Google doesn’t suggest, instead it would send me to the car packed 4-lane highway.

Playing around with the marker, the routes get a little funkier:

  1. It’s not the shortest/quickest route. Bike trails are clearly weighted very high in the algorithm.
  2. You’re allowed to ride through the Boston Common, but not through the Public Garden as the algorithm suggests; missing restriction.
  3. The shown bike facilities in Cambridge are pretty messy and Boston looks way better than it actually is – Mass Ave preferred for bicycling? That’s one of the craziest streets you could possibly ride on.
  4. At Kendall the algorithm clearly gets confused with some turn restrictions and would send you up and down the street.

Despite those few glitches, Google has done an amazing job in introducing bicycle transportation to Google Maps – very exciting!

Busted!

Published on March 9, 2010 in Random Box. View Comments Tags: , , , , , .

For the first time in my life I got pulled over on my bike. It was three of us running a red light this morning in Cambridge (Hampshire / Windsor btw). To be clear: there were absolutely no cars in the street we were crossing. No suicidal attempts or speeding blindly into a busy crossing. Just a totally empty street and a cop hiding between parked cars on the other side.

At least it was a cop on a bike, so we were all somewhat equal. The first cyclist tried to fight it, claiming the light was green. “Here is a $20 fine that you can fight”, said the cop, who apparently was not in arguing mood at all that morning. I and the cute blond girl switched to “Yes Sir, sorry Sir” mode and got away with a warning. Or maybe it was just the cute blond girl effect.

Cambridge bike ticket

My favorite: “Car Alarm Over 10 Minutes” for $300 – nervous car security systems can be expensive in The People’s Republic of Cambridge!

Wrapping up Gov 2.0 Camp New England

Published on March 7, 2010 in Geomensch. View Comments Tags: , , , , , .

Gov 2.0 Camp New EnglandI had a fantastic time yesterday at Gov 2.0 Camp New England and enjoyed the event a lot. In particular I was very impressed by the interest of the public sector. I wouldn’t say it’s typical that an event, held on a Saturday, which happens to be the first nice spring day in Boston, attracts so many government employees, ranging from the governor’s office to local town administrations, and affiliated organizations. Throughout the event you could feel the commitment to work on better and more inclusive governance at all levels.

My personal highlight was the first session I attended, about Open 311. It’s clearly not my core area, but I’m interested in the current development and felt that I learned a lot in that session. One of the most interesting points during the discussion was the evaluation of “Resistat”. Resistat is an initiative to include residents in 311 statistics in Somerville. It works very simple: a mailing-list facilitates communication and statistics and results are sent out to residents as powerpoint files. Not rocket science, but it’s enough communication technology that even though only about 25% of involved residents have been to in-person meetings, 85% of them say that they feel better engaged with their local government (by sending powerpoints to a mailing list, it’s as simple as that!). Anyway, great insights when talking about the “town hall meeting divide”, can’t wait to read the entire study about the program.

Our session about Open Data Strategies was “merged” together with I think 5 other sessions that had the word “data” in the title. Unfortunately it didn’t really work out as we intended it and the discussion went somehow all over the place. Better luck next time I guess.

The last session I picked was all about data visualization. Two young IBM researchers showed and demoed amazing data visualization tools – Many Eyes and sense.us among them. Their latest project, called “IBM Visual Bill explorer”, should make it easy for citizens to visually explore and analyze legal texts. Tremendously valuable when trying to understand or to find potential pitfalls in 1000+ pages documents written by lawyers, as bills usually are.

On a side note: I had absolutely no idea that IBM is running such a great research department. Where are marketing departments when you really need them?

Happy hour – free beer was involved – went straight to talking GIS and Open Source. As it turned out, there are very similar problems across gov agencies (surprising, huh!). One notion during the discussion was, that, instead of throwing money individually at our problems, why not join forces and contribute to and customize Open Source projects where we all benefit from? Interesting thought, will be continued…

Python Flickr API geo-search example

Published on February 25, 2010 in Geomensch. Closed Tags: , , .

I just started using the wonderful flickrapi Python interface for, well, searching Flickr for geocoded photos around given locations. It’s fairly easy to use and does most things for you. You start with a Flickr API object…


import flickrapi
api_key = '1234567890'
flickr = flickrapi.FlickrAPI(api_key, cache=True)

…replace some dots with underscores in the Flickr API methods…


photos = flickr.photos_search(tags='boston', lat='42.355056', lon='-71.065503', radius='5')

…and loop through the parsed results…


for photo in photos[0]:
	print photo.attrib['title']
	photoLoc = flickr.photos_geo_getLocation(photo_id=photo.attrib['id'])
	print photoLoc[0][0].attrib['latitude']
	print photoLoc[0][0].attrib['longitude']
	photoSizes = flickr.photos_getSizes(photo_id=photo.attrib['id'])
	print photoSizes[0][1].attrib['source']

…done.

The above code example lists title, latitude, longitude and thumbnail-source of photos found in a 5km radius search around the Boston Common.

Crowdsourcing bicycle routes

Published on February 3, 2010 in Geomensch. View Comments Tags: , , , , , , .

If I had to think of a solution to start creating a bicycle routing system, I’d do exactly what The San Francisco County Transportation Authority has done: create smart phone apps, gather information where cyclists are riding, data mine those tracks and build route suggestions on top of that knowledge.

Bicycle routing is in my opinion far more complex than car routing. Car routing is mostly based on well known and documented rules, also known as road traffic regulations. Mix in estimated traffic figures, average speeds and fuel consumptions and you get pretty decent car directions.

For cyclists, a similar rule set exists, but it’s maybe a little more, let’s call it, elastic. Cyclists use short-cuts, turn where cars can’t, go against traffic, ride through parks and on poorly documented trails. High traffic doesn’t mean slowdown for cyclists. They ride by on the bike lane on the right side of a traffic jam at almost the same speed as without traffic. But high traffic creates a security risk some cyclists aren’t comfortable with taking and rather choose a different route.

A perfect route from A to B for speedy messengers doesn’t necessarily mean it’s also an ideal route for kids. For your daily commute you probably pick another route than for weekend rides, even though it connects the same points.

Bicycle routing criteria is manifold, sometimes psychological, hard to measure and to quantify. Researching how cyclists are going, for what purpose and under what conditions, is a very smart way to get started on that topic.

Re-projecting vectors in JavaScript

Published on February 1, 2010 in Geekery and Geomensch. Closed Tags: , , , , , , , , .

I know, it eventually all boils down to maths. But it still blows my mind that you can re-project geographic features on-the-fly with a few lines of JavaScript in a web browser.

How?

There is this great library PROJ.4, that does everything you’d ever want in terms of cartographic projections. A few smart people have ported PROJ.4 to JavaScript, called Proj4js then.

Proj4js works great in combination with OpenLayers, a popular JavaScript web mapping framework, and allows on-the-fly projections between any spatial reference systems browser applications.

<script src="proj4js-compressed.js"></script>
<script src="http://openlayers.org/api/OpenLayers.js"></script>

Define the spatial reference you’re planning to use. Check Spatial Reference for the exact projection parameters and include them in your code.

Proj4js.defs["EPSG:26986"] = "+title=Massachusetts Mainland NAD83 +proj=lcc +lat_1=42.68333333333333 +lat_2=41.71666666666667 +lat_0=41 +lon_0=-71.5 +x_0=200000 +y_0=750000 +ellps=GRS80 +datum=NAD83 +units=m +no_defs";

Adding all desired projections to the OpenLayers script…

projOSM = new OpenLayers.Projection("EPSG:900913");
projWGS84 = new OpenLayers.Projection("EPSG:4326");
projMassGIS = new OpenLayers.Projection("EPSG:26986");

map = new OpenLayers.Map ("map", {
	maxExtent: new OpenLayers.Bounds( -20037508.34, -20037508.34, 20037508.34, 20037508.34),
	maxResolution: 156543.0399,
	units: 'm',
	projection: projOSM,
	displayProjection: projWGS84,
	allOverlays: false
});

osm = new OpenLayers.Layer.OSM(
	"OpenStreetMap",
       "http://tile.openstreetmap.org/${z}/${x}/${y}.png"
);

openspace = new OpenLayers.Layer.WFS("Open space", "http://giswebservices.massgis.state.ma.us/geoserver/wfs", {
	typename: "massgis:GISDATA.OPENSPACE_POLY"
}, {
	projection: projMassGIS
	attribution: "<a href='http://www.mass.gov/mgis/'>MassGIS</a>"
});

…results in an interactive map with MassGIS Open Space WFS vector features overlayed on an OpenStreetMap base layer, using WGS84 lat/lon as display coordinates.

On a sidenote: OpenLayers comes with a Python proxy to retrieve information from remote servers via an XMLHttpRequest. Here is a good how-to get Python play well with IIS 6 on Windows Server 2003, which was quite useful.

Don’t forget to add the domains you’re trying to access to the Python proxy. For MassGIS you would add following string for instance:

allowedHosts = ['giswebservices.massgis.state.ma.us']

Heating up SVG

Published on December 12, 2009 in Geekery and Geomensch. Closed Tags: , , , , , .

Last week I came over Raphaël, a great JavaScript library for vector graphics visualizations, and I started playing around with maps and SVG again. Long time no see!

To bring some map content from ArcMap to Raphaël I used the VBA Macro I wrote 4 years ago in ArcMap. It still does the job and gives me clean vector graphics the way I want them. I couldn’t find a decent SVG export option for QGIS, although there are some efforts to improve that kind of functionality.

AsSVG, a Python geoprocessing script for ArcGIS is pretty good too. It provides some nice export options, such as pick style and data attribute fields, and I actually ended up using it a lot.

However, it’s 2009 and there are other ways available for sharing code then just providing a plain text file. So I ended up wrapping a bitbucket repository around it. Just in case if somebody is interested in working on or improving the script…