The 1562 map of Bruges by Marcus Gerards

Cartography is subjective. This is a well-known fact borne out year after year, map after map. The early Christian church sponsored T-O maps that showed the world as a metaphorical “body” of Christ. Automotive companies funded city maps from the mid-20th century that plainly showed highways and boulevards with rail and tram lines in diminished (or invisible) marks. Or contemporary “post-modern” maps that turn the world inside out and show spaces and boundaries not visible to the naked eye (see e.g. Mission Possible).

One striking example of subjective cartography is this map of Bruges from 1562. A massive, beautiful map. Originally etched on 10 separate plates, printed and composited into a 70×40” masterpiece. At first glance, this map is startling in its obsessive detail and precision of line. But the map’s precision is only a feint at geographic accuracy and serves to distract — like any good magician — from the map’s illusion and intended purpose.

Bruges, it should be noted, is an obsessively precise city: its center a mess of medieval streets perfectly and proudly preserved. Bruges is in northwestern Belgium, near Antwerp, the North Sea, and other ports of the Flemish region. Just across the narrow sea is the Thames and London, and the port lies almost equidistant from the Baltic and Mediterranean seas. The region has long been the commercial hub between major shipping lanes and the overland trade-routes of inland Europe. A trip down one of the city’s wistful canals or cobblestone streets will no doubt impart that Bruges was one of the prosperous and wealthy centers of this trade.

The medieval character of the city is undeniably interesting and well-preserved, spiting the bombs of the world wars. In the 1970s, the city experienced a modern Renaissance, first being adopted as a World Heritage Site and subsequently experiencing massive reforms to city planning that enabled the preservation of the inner city and its tourism while promoting industrial and residential growth in other neighborhoods. For example, automobiles would disrupt the pedestrian-scaled inner streets of the city, and so are parked in lots “extra-muros.” (Tour buses, thankfully, suffer the same fate.) Commercial development of main corridors is encouraged as channels for tourists, but similar painstaking efforts keep other alleys and streets quieter for citizens. The city’s many medieval and Renaissance facades have been refurbished, and to this day the churches are being repainted and re-frescoed to their original splendor.

Given the place’s obsessive and picturesque quality (a quality darkly parodied by the film In Bruges) it’s no wonder that a map of the place should articulate the same kinds of obsession. The medium — etching — is of course almost incapable of producing anything but such fine lines. But the cartographer Marcus Gheeraerts the Elder (Marcus Gerards) pushes his rendering further. He starts with painstaking surveys of the old city, applies precise architectural renderings to the city’s key landmarks (the Belfort Tower, the Church of Our Lady, etc.), then imaginatively decorates the margins with peasants, boats, geese, sheep, and cows — rarely to scale. The gold and teal palette is striking. And the result is a glorious mess of stories and meaning: each detail eye-catching and brightly distracting.

All of this, however, mask a larger illusion. The map shows a city that is almost too perfect: surrounded by a delicate-but-bargeworthy circlet of a canal, its gold landmarks tall and proud, wide canals clearly marked, wide streets for trade, easy river access to the sea. But so much of this, from a more “correct” 21st century viewing via satellite, is just plain wrong. For starters, the canal encircling the city is shaped more like a dented avocado than a jeweled tiara. The canals and streets are much narrower than they appear. The Grote Markt (Central Market) and Belfry are not at the literal geometric center of the city, but would be more accurately drawn further to the east. The river is too wide, the sea much too close.

When comparing with satellite photos, it’s clear how “inaccurate” the 1562 map is

The sum of Gheeraerts’s manipulations to geographical accuracy result in a Bruges that is at the center of a bustling commercial empire, closely linked to the sea and ripe for trade. In fact, “when the city council gave Gerards the commission, they were acutely aware that the silting up of the River Zwin, linking Bruges with the North Sea, had made access to Bruges much more difficult. Consequently, they told him to make the river and its tributaries look wider than they were.” (source) Advertising sea access with a well-drawn map encouraged traders from afar to engage with the Bruges economy and declared its prominence on the world scene. In hindsight, it’s unclear how well the advertising worked: the so-called Golden Age of Bruges ended in the 16th century, and not until the 19th century did strong economic prosperity return to the city.

Indeed, a map with a purpose. The rendering remains a popular artifact in the history of Bruges. Copies decorate many walls in the city and it is oft-referenced by tour books and historical essays concerning the city’s landmarks. (One citizen went so far as to obsessively build Gheeraerts’s map to scale with 3d models.)

And indeed it is a delightful map: imaginatively playful, stark and purposeful, precise and utterly bold. A proud map for a proud city.

Thanks to Elisa Colombani and Nathan Mueller for reading earlier drafts of this post. Further research on this map is happening at MAGIS Brugge.

How to improve A/B testing with Mixpanel

“We enjoy using Mixpanel and enjoy A/B testing. In this post we show how to use Mixpanel’s API and our own open-sourced A/B testing statistics package to easily create A/B tests in Mixpanel.”

Know your latency: a simple hack using Graphite and Memcache

“At Thumbtack, we’ve long tracked our server response times. But what we really wanted to know was how long it took a user to go from an initial request to having a fully rendered page, domReady and all necessary Javascript loaded up from the CDN. Our answer is to combine Memcached and some jQuery callbacks to track total application responsiveness.”

Thumbtack eats amazing food, but it’s not by accident. Eating lunch together is the single most important culture-building activity we do. Some of the rules include “Have a weekly all-hands dinner”, “Hire a chef”, and “Don’t buy vending machines.” Building a healthy food culture keeps everyone happy and healthy.

Read the full story.

Sponsored by the Chez Panisse Foundation

The Chez Panisse Foundation is supporting an initiative to make good, local food a part of every school: the Edible Schoolyard. The first edible schoolyard was established at the Martin Luther King, Jr. Middle School in Berkeley, and it has proven to be radically successful. This summer, the Foundation is spreading awareness about the program with an Eating for Education dinner on August 27. I was fortunate enough to be involved in this remarkable project.

Eating for Education a grassroots effort to create national awareness about school garden and school lunch programs. the campaign will culminate in homes and restaurants around the country on august 27th with special dinners celebrating the building power of edible education. get involved: learn more, host a dinner, or eat out for education!

Learn more at Eating for Education.

Rotary Maps powering the Thumbtack realtime dashboard

Cross-posted from the Thumbtack engineering blog. I recently released an open-source mapping toolkit called Rotary Maps that helps you make realtime maps on top of Google Maps v2 or v3. It also supports making maps in a simple DOM element if you don’t care for Google Maps. Check out the full post at the Thumbtack engineering blog.

Telephone calls and regional connections in Great Britain

These maps are fascinating.

Have you ever wondered why state or county or city boundaries are drawn where they are? It turns out that administrative and government boundaries are consistent with trends in human relationships; that is, people associate most with others in the same government-defined region.

To investigate the geography of human relationships, a group of researchers has mapped human relationships in Great Britain using telephone calls as a proxy for intensity of relationship. Specifically, Ratti, et al. used total call time (scaled so as to take into account local population densities) as an indication of relationship between two people.

Quoting:

… we would indeed expect an agreement between the administrative boundaries and those found from human interaction, as they probably evolved together, over many centuries of mutual interplay—cohesive patterns within society promoting change in administrative boundaries and the latter, in turn, affecting human interaction.

The research was done by Carlo Ratti, Stanislav Sobolevsky, Francesco Calabrese, Clio Andris, Jonathan Reades, Mauro Martino, Rob Claxton, and Steven H. Strogatz. More information can be found here: Redrawing the Map of Great Britain from a Network of Human Interactions.

Hierarchy of Linux vs E. coli internal network controls

A recent paper from the National Academy of Sciences compares the internal control hierarchies of Linux computers with E. coli bacteria. Specifically, the paper compares a snapshot of the Linux call graph to the cell’s transcriptional regulatory network. The cell’s network

coordinates gene expression in response to environmental and intracellular signals, resulting in the execution of cellular processes such as cell divisions and metabolism.

Researchers discovered that the internal bacterial network hierarchy is bottom-heavy, with most of the work performed by many specialized modules, with little direction from the top of the hierarchy.

In contrast, Linux control hierarchies are top-heavy: a few reusable workers at the bottom of the hierarchy are called by many top-level and middle-level components: “From an engineering point of view, the reuse of common nodes between modules is a cost-effective way to construct a complex system.”

An interesting conclusion from the paper:

As the genome of an organism grows larger, it can reuse its tools more often and thus require fewer and fewer new tools for novel metabolic tasks. In other words, the number of enzymes grows slower than the number of transcription factors when the size of the genome increases. Previous studies have made the related finding that as one moves towards more complex organisms, the transcriptional regulatory network has an increasingly top-heavy structure with a relatively narrow base. Thus, it may be that further analysis will demonstrate the increasing resemblance of more complex eukaryotic regulatory networks to the structure of the Linux call graph.

Reference

Comparing genomes to computer operating systems in terms of the topology and evolution of their regulatory control networks. Koon-Kiu Yan, Gang Fang, Nitin Bhardwaj, Roger P. Alexander, and Mark Gerstein. Yale University. PNAS, May 18, 2010. [full article text]

A great talk about Christopher Alexander’s Notes on the Synthesis of Form.

In The Design of Design, Frederick Brooks takes aim at the problem facing every engineer and designer: how do you architect and build a complex system? The question is especially pertinent to computer scientists and programmers. Below are a few notes from the book.

Takeaways

The Waterfall Model is wrong. Not only because it limits the flexibility of design, but also because it so poorly describes how development actually happens. It is inaccurate and crude, and does not promote good design. But all is not lost. Even though the Waterfall Model is a poor choice, a design methodology can be valuable. It guides the design process and gives structure to team collaboration and communication.

Brooks discusses several software design methodologies, ultimately backing to the Spiral Model. This model closely matches how many teams actually work. The Spiral Model starts with a definition of the system’s core concepts and objectives, spiraling out into mockups, prototypes, and finally an operational product. It suggests an evolving “outward” process flow, guiding the product “out” into production. It also articulates the consistent need for review and risk assessment at each stage of an iterative process.

Although these models are useful for guiding the design process, a Chief Designer needs to be at the core of the process to ensure conceptual integrity of the design (language, interface, visual design, and so on).

The user interface, the users’s crucial system component, must be tightly controlled by one mind. … In large architecture teams, the chief architect’s scope is too large for him to do the interface himself. Nevertheless, one person must do it. If one architect can’t master it, one user can’t either. (p 72)

The best products are always spearheaded by one or two visionary thinkers: consider the greatness of the Macintosh, UNIX, Python, FORTRAN, etc, versus the lackluster PC, Windows, Appletalk, or Cobol. Brooks then argues that it is the role of supporting management to get out of the way of the Chief Designer and her team, giving the designer ultimate authority on design decisions, protecting the team from unnecessary meetings and interruptions, etc. to encourage flow and creativity.

Great designers articulate user profiles. A written description of each kind of user helps to discover and define assumptions about the design, and guides the entire team.

Great designers also actively research the work of other great designers. An anecdote:

Bach took a six-month unpaid leave from his job and walked 250 miles to study the work of Buxtehude. (He lost his job for overstaying his leave.) Bach proved to be a much greater composer than Buxtehude, but his surpassing excellence came from comprehending and using the techniques of his predecessors, not ignoring them. (p 154)

Finding exemplars in the field of computer science is not hard, but few programmers today take the time to read code and investigate systems. More could be done to encourage students, especially, to research the excellent work done by their predecessors.

Summary

The Design of Design is highly recommended. It provides a wealth of information about the design process from someone who has designed beautiful systems (and some not-so-beautiful), with plenty of real-world examples and insights. A must-read for anyone who is designing software.

Map of California County Populations produced with Cartographer.js

The most recent release of Cartographer.js supports county-level choropleth maps. This was the number one requested feature for Cartographer and I am delighted to finally be able to offer it in an official package. Many thanks to Ben Cohen and Xanthippe Wedel for making this a reality. The image above is a snapshot of the California county populations map.

Counties are drawn using the same efficient polygon encoding as states, and they can be easily referenced by name. All color schemes and other choropleth map features work for counties just as they worked for states. Click here to download Cartographer.js v0.4 with full county support.

Some additional notes about this release:

• Loading all US counties into a Google Maps is quite a challenge, and it’s recommended that you only use Cartographer’s county mapping facility for a few states at a time unless you wish to stall out older browsers. Google Chrome handles the large datasets gracefully, if slowly.
• Adding counties increases the filesize of Cartographer.js significantly. If you don’t need counties, feel free to use an older version for now, and this should be fixed in an upcoming release.

Enjoy!