Friday, 13 June 2014

Pedantic cartography

As regular readers know, this entire blog is set up to fight the fight against cartofails. It's written in a jocular style with my British sense of dry humour. I was born with it. It's just the way we're built. Where I can I provide clarification on why a particular map fails and how it can be improved. Occasionally I even re-work stuff to show a 'better' alternative. Remember, this blog began with my correction of the True Size of Africa cartofail by Kai Krausse and my very first blog post.

I recently did a reworking to show where The Proclaimers may have reached in 500 miles. Over the last few weeks it's picked up quite a head of steam and been featured in Slate, The Atlantic's Citylab, got to Number 1 on the Reddit Mapporn sub-Reddit and even warranted a post by that most nonsensical Twitter account @Amazing_Maps. And today it again popped up in The Telegraph...once a respected, though very right wing, British newspaper. All terribly prestigious coverage for what must rate as my most frivolous mapping project ever.

This latest effort by James Edgar has me wincing and has my friends and colleagues chortling into their corn flakes. Edgar has reworked the story from a collage of other sites and it shows. I'm introduced as a pedantic cartographer. Yeah yeah, maybe that's true but why is it that virtually every cartographer get's labelled as pedantic, picky or awkward as if it's a fundamental flaw in our character? These labels stick and really don't help the cause. It's like every scientist has to be a boffin or, dare I say, every journalist is accused of lazy journalism. Actually yes...that's exactly the point. Lazy journalism.

How does correcting a common mapping error by making the effort to show and explain the error with the intent of improving people's appreciation of maps become something to deride? Pedantry is an obsession with 'minor rules'. Sorry pal, but these minor rules actually become very important in mapping even if you neither care nor know about it.

It's not about precision as Edgar suggests...I was not making a more precise map...I was making a correct map for the projection used (Web Mercator). Apparently I "created an accurate projection". No...I did no such thing, the projection already exists. What I did was map correctly on top of it. He goes on that I explained that "simply drawing perfect circles around the start point on a flat world map would not offer a true indication of where they could get to". Actually I didn't say that. You can draw perfect circles on any flat map that uses a conformal projection. You cannot on Web Mercator (actually, strictly speaking you can...they just won't be perfect circles when projected back onto a spherical surface). It's a function of the mathematical projection, not the fact the map is flat. Apparently I then used a "clever computer tool called a Web Mercator". Seriously? Did you not even use Google to check Wikipedia to find out what Web Mercator actually is?

Comments are not enabled on Edgar's post so I have no right of reply. He didn't contact me before running the story so i cannot even claim I've been misquoted.

Let me finish off with some true pedantry. Edgar refers to me as Mr Field. It's actually Dr. Yeah, that's pedantic but heck...I have a qualification in my area of expertise.

The Telegraph? Wow...more like the Daily Mail.

Wednesday, 28 May 2014

Testing..testing...1, 2, 3.

I was reminded this week of a number of ways in which you can assess cartographic work in simple ways. A conversation between Alberto Cairo and Moritz Stefaner trod over some old ground but their conversation is worth exploring because much of what I see fails these simple tests (and leads to me blogging). They debated the first and second of the simple tests I set out below. I added the third. These are tests that I (and many others) apply when looking at and critiquing maps. They are the basic tests that anyone can apply:

So What?
The first test is simple...does the work you are looking at leave you asking so what?. This is how we used to assess student dissertation proposals and get them to reflect on whether their proposal was worth doing. Was it persuasive? Did it make me want to know more...to explore or find something out? Did it make me care? All maps ought to, at some level, inspire their intended audience to want to care about what it is that's being illustrated and the message of the map. It has to have a function and if the form is well crafted that function should be visible. The map may very well have a good purpose to the map-maker but has that been extended to an audience?



This isn't an exact science though. Different people and user groups have different so what thresholds and so what works for one may not necessarily work for another. This is where a consideration of the audience comes in when you are making a map. Engage your audience first. Bring along others if you can. Pleasing everyone all the time is impossible though.

It's also perfectly reasonable to experiment and at the moment we're in a period of cartographic development where technology is out-pacing best practice. Animation and 3D are just two areas that we've always played with but now the tools are mature enough to allow people to really get their hands dirty...and they are. At the moment there's too many failing the so what? test. This may not be a bad thing IF it leads to new ways of working that make good use of the techniques.

Ah-ha!
Let's assume people have got past the so what moment because, let's face it, if they haven't then they've already clicked to another web page or left dissatisfied with your work. Upon inspection, does the map give you some sort of mini-eureka moment? Is the message communicated with clarity and has the map-maker made it legible? Clarity and legibility are key though they are not the same thing. Clarity relates to the message. Has the message been encoded into the map's syntax effectively. Legibility is the way in which the map-maker has brought focus to that message through effective graphical structure.

Put simply...do you get it? This is the ah-ha! moment when you realise what it is you're supposed to learn or find out. It should come relatively easily.

The person that reads your map should leave with a deeper understanding of the theme or topic. They shouldn't have to work too hard to gain that understanding either. The ability of the map-maker to make you care enough to want to look at the map and give you some sort of clarity about a topic is what good cartography is about.

The squint
Does the story of the map immediately jump out at you? Given we cannot rely on people spending that much time or effort viewing your map, making the message legible is crucial and this has a lot to do with your ability to structure your map. This is down to what British geographer William Balchin termed graphicacy. He coined the phrase in a 1972 address to the Geographical Association. Graphicacy is the natural counterpart to other cognitive intelligent processes of communication such as literacy, numeracy and articulacy. Maps and other spatial documents are the tools of graphicacy and the very basis of geography. Cartography is the professional application of expertise in graphicacy.

Becoming proficient in graphicacy will help you tell your story more effectively in the same way that effective writing or speaking skills helps you communicate using the written or spoken word. If you know how to speak in a graphical language then you're half way to being able to communicate your message. This goes beyond knowing constructional techniques and mechanics for knowing how and when to use certain graph or map types though. It's just as much about how you organise them on the page or screen. While written and spoken language comes at us in serial...one word after another in a sequence that our eyes follow and our brain systematically decodes, pictures arrive at our eyes in parallel. Maps are presented all at once. So we need to encode them so that certain components appear more prominently to give our brains a chance at decoding into some sense of order. These lead the eye. they may be larger or more visually prominent, they may use lighter or desaturated or bolder or more saturated colour, they may appear in a certain animated sequence or they may require interaction but doing a squint test is a good way to determine whether what you are looking at is communicating well.

So...sit back as if you're in a wild west film, chewing on a cheroot and pretending to be Clint Eastwood. then squint and look at the map. What do you see? If you can still make out the main features and the central topic of the map then chances are it's got its graphical structure well proportioned and balanced. It's a simple way of seeing whether what you are seeing is what your brain is receiving. If your eyes are picking out peripheral or less important components under this test then that's going to cloud the message. There is some science behind this...what you're doing when squinting is reducing the amount of light entering your eye. Your peripheral vision is also impacted. You therefore have lower levels of visual acuity (visual resolution) and so you are trying your hardest to pick out key shapes and features.

And finally...some words from a master
As with everything, there will always be examples that break the rules. there will always be innovation that overrides some of this so be mindful of that when looking at maps. Also, remember that the value of a map is going to vary between audiences so that will undoubtedly affect your impression. Then there's the final matter of subjectivity. While the above are semi-objective tests there's no doubt that we all have preferences for certain types of maps and particular looks and feel. Do you prefer Monet, Turner or Banksy? We all bring our subjective preferences to the table.

In the week that the great designer Massimo Vignelli died it's worth reflecting on some of his basic tenets in design and thoughts on why experts in a field are important in the context of shaping best practice. This gives context to the simple tests described above:

"I like design to be semantically correct, syntactically consistent, and pragmatically understandable. I like it to be visually powerful, intellectually elegant, and above all timeless."

"If you can design one thing, you can design everything."

"I thought that it might be useful to pass some of my professional knowledge around, with the hope of improving [young designers'] design skills. Creativity needs the support of knowledge to be able to perform at its best."

"If you do it right, it will last forever."

"The life of a designer is a life of fight against the ugliness."

"There is no design without discipline. There is no discipline without intelligence."

"Good design lasts longer."

"...and that is why I love Design."

The three tests outlined here are basic things you can do to see if your own designs are working and to look at whether other designs are working. It's not rocket science but it may just help you to take a step back and reflect on the quality of the work. There's lots of fancy ways to make maps but fundamentally...are they working?

Saturday, 24 May 2014

LyricMap: Where the Streets Have No Name

Inspired by the nonsense mapping of The Proclaimers 500 miles that I re-mapped, I was pondering a few other geographical lyrics and how they might be mapped. I'm going to call them LyricMaps ™ and there's a lot of them. First up -let's give U2's Where the Streets Have No Name a whirl and see what we come up with.

First, start with a nice healthy dataset of all streets in the contiguous USA and use some Geographical Information Systems savvy to process it. I'm fortunate to have access to the 2012 version of the Tom Tom data for North America which contains over 15 million street segments.

Second, apply a few of query analyses to extract any street segment without a name, discounting outliers like connectors, ramps, slip roads and such like. The result: a LyricMap of 3.5 million streets with no name, the beauty of which is that I don't need to worry about labelling because, well...there aren't any!

Finally, map each road segment with a huge dose of transparency so at the final scale the map shows areas that contain relatively few streets with no name as dark as the background. Where there are numerous streets with no name, the overlapping transparent symbols create a much lighter effect.


The map deserved to be styled as an homage to U2's classic 1987 The Joshua Tree which contains the track.

The overall pattern suggests that it's streets in rural areas that have no name. Pretty much all the major cities appear dark indicating a low number of streets with no name. This makes sense...the dataset contains every road in the U.S. and many of them would be dirt tracks. Despite there being over 3 million separate segments on this map there isn't much sense looking at the detail for a particular city...there are so few it makes the map sparse as the following larger scale map of California illustrates.



That said, if you want a giant 36 inch version at 300dpi then you can download one here. It's 12Mb.

Of course, there's more work that could be done to eliminate more categories of roads but hey - this is just a bit of fun. I've got plenty more geographically inspired LyricMaps planned so stay tuned!

Acknowledgments: Tom Tom data used and published under licence using Esri technology.

Wednesday, 21 May 2014

I would map 500 miles

When The Proclaimers released Sunshine on Leith in 1988 I was just about heading off to University (to study cartography and geography - that bit is important). They were not to my musical taste...why would I want to be beaten up for liking such a dreadful duo? Little did I know that over 25 years later I'd be making a map relating to one of their first and most celebrated ditties I'm gonna be (500 miles). If you want the background read on...if you want to see my map, scroll to the bottom.

The song is renowned for the lyric But I would walk 500 miles. And I would walk 500 more...blah de blah blah.... And so fast forward to 2014 and the following popped up in my twitter stream.

Now it's clearly tongue in cheek and fair play to Hazel McKendrick...I haven't seen anyone tackle this cultural dilemma before and she had a good go. Where, indeed, were The Proclaimers going to walk 500 miles to from Leith? And what about the 500 more? Unfortunately she used two perfect circles at the nominated distance around Leith but too late, another viral map is born and all the usual suspects begin clamoring to heap praise upon it.

I and a number of map-minded people folded our arms and began finding fault because the circles shouldn't be so, well...circular! Yet again someone had done something wrong on the internet (thanks to Barry Rowlingson for reminding me of the well observed XKCD cartoon).

Great idea. Nice bit of fun but...wait...the Web Mercator projection distorts shapes and areas pretty markedly. If you draw a line indicating 500 miles around Leith on that projection it would not be a circle.

Here's the classic example from The Economist on the threat from North Korean missiles that made the same mistake...


And here's the correction they were forced to publish after they had redrawn the lines properly and with respect to the projection used for the map...


Now it's questionable whether marking the range of North Korean missiles incorrectly is more or less dangerous than the lyrics from The Proclaimers (I guess it's a question of taste) but either way McKendrick's map is wrong. And then what about the fact that reaching Iceland would require them to walk on water? Now we're stretching the bounds of their talent just a little far with that one surely!

So, as a self-respecting cartonerd I re-did the map...



I still used Web Mercator and placed 500 mile and 1000 mile geodesic buffers around Leith (using the same huge assumption as McKendrick) to show the real distances as they appear on this map. These represent the theoretical extent of how far they might walk so if they went off-road and walked in a straight line that's where they would end up (notwithstanding the small matter of the wet stuff).

I also went a little further and used a bit on analytic acumen to calculate how far 500 miles would take them using the European road network. Then I calculated how far they could get by going 500 more. Those areas I show as shaded so we can see how far they would walk on land. I took some liberties...I presumed they only walked on roads and of course, they may know of sneaky short-cuts or go roaming cross-country. I also presumed the ferry journey's equated to a walking distance when they most likely sat down and had a rest (though if they walked round the deck then the eventual distances need reducing slightly)

It's not perfect (there's no North Sea ferries to Scandinavia and the Brittany ferry is also missing) but it's better than shoving circles on a Web Mercator projection and calling it cartography. The correct version applies knowledge of how maps work to make a sensible, correct map...even though the theme is distinctly daft and I still hate the song with a passion. I hate poor cartography more though.

That said, McKendrick's map has nearly 2,000 retweets at the time of writing. Mine? 88. Proof positive that actually nobody gives a shit about quality anymore...or when someone has gone to the effort of providing a correction they do their very best to ignore.

Update: Thank you to all the people who have read this since posted. And a particular thank you to all the other nerds out there who have found fault with my version. I have updated the map to make the necessary corrections and disclaimers.

Update 2: I couldn't resist...I did a Where the Streets Have No Name follow-up map...and I'm now thinking of all the other geo-related maps that can be made. I'm calling them Lyric Maps.

Update 3: Funny how frivolous work gets noticed...I've written an update in a new blog post called Pedantic cartography.