Wednesday, 20 July 2016

Taste the rainbow - third helpings

If I'm going to have a carto-argument I may as well have it with the President of the United States.

Today, President Obama used this tweet to encourage us to be aware of rising temperatures and the need to stay safe and watch out for others. I have no qualms with the intent but as you'll appreciate, the cartonerd in me got quite irked by the leading statement.

"This map says it all". Well despite rainbow colour schemes being used to death to map anything and despite people preferring their own facts and telling me everyone understands the scheme I resolutely beg to differ.

I wrote about this problem several times before herehere and here. And so have others here, here and here. Rainbow colour schemes do not work well for numerical data where the analytical task is to determine what is higher and what is lower across the map.

Put simply, our brains do not process colour (strictly speaking hue) in a way that tells us a quantitative difference between them. Different hues (yellow, red, blue etc) work very well for showing qualitative differences on a map. Single hues, that vary from light to dark, or even a dichromatic scheme that blends a couple of colours do a much better job at encoding a quantitative difference.

In the map above, there's no logical consistency in the brightness of the colours. Some stand out more than others. Magenta is arguably the colour we see as the brightest yet there's a sort of light cream colour in there that actually means 'more'...and that's before we get to yellow. Yellow is not 40 degrees hotter than cyan on the spectrum either. Rainbow schemes are not perceptually uniform, they modify meaning beyond what the data supports and create visually false boundaries. You could also easily reverse the scheme and it'd make just as much sense.

The argument that people understand it is borne out of the simple fact they see them every day so they believe they understand them. They're conditioned to them. It's called brainwashing. I get it, We're all liable to a bit of brainwashing from time to time and just because you relate hot with red and cold with blue then it's all good OK?

Well no...because on this map yellow, magenta, a light pink and burgundy is hotter than red which happens to be in the middle of the spectrum. And how hot is green exactly? I've never been green-hot. I would still argue vehemently that without a legend these sort of maps are harder to interpret than they need to be.

Given in every other aspect of life people seem to want the easiest, laziest path of least resistance to something, why they force their brains to interpret rainbows baffles me. More so, the arrogance of constantly using your own facts to contradict cognitive science just shows a complete unwillingness to accept a better way. Hell, rainbow palettes aren't even 508c compliant!

End rainbows! #endtherainbow

Saturday, 16 July 2016

Chip paper silly season

It's likely most will have already forgotten that a few days ago the Wall Street Journal published a short article on Null Island. After all, today's news is tomorrows fish n' chip wrapping.

A couple of months ago a journalist contacted me wanting to chat about this mythical place he'd heard of. I agreed. It was supposed to be background for the piece he was writing but I made it clear I was not qualified to be regarded in any way as an expert or even protagonist for the rise of the Republic of Null Island. We spent well over an hour chatting about basics of cartography, maps and such like. We got into coordinate systems, datums, map projections and so on.

I never got to see a draft of the article but there it was, front page of the Wall Street Journal. In some ways it was a nice piece for a general audience but tucked away was this fantastic quote I'd apparently made: “There is a lot of terrible-terrible-terrible math involved,”. Did I say that?

To be honest I can't recall but the conversation was about the need for different local coordinate systems and because the earth was a geoid (I never said lumpy egg-shape) that involved maths to make flat maps. I am liable to the odd quip but I can't recall saying 'terrible' three times. Maybe I did, but the point I was making was that making maps involves maths and it can get rather complicated whereas the article juxtaposed that alleged quote with something unrelated to what we'd discussed.

By the way, that's maths with an 's' because I speak English English, not American English. I entirely understand the s being dropped as it's a U.S. publication but it did cause amusement among a good number of my geo-pals.

The paragraph then went on to label me a 'Senior Cartographer'. Umm - nope. No such job title at the place I work. The full title of my employer was written out (despite it hardly ever being used these days to my knowledge) and then another alleged quote was appended: “Every part of the planet differs from every other part and that is why we have all these different maps.” shit Sherlock! Again, I was actually referring to different coordinate systems as context for that but clearly that was deemed irrelevant.

So what's the problem? Ultimately it's just a media piece. My grand contribution boiled down to two pretty pathetic alleged quotes in an otherwise decent piece.

The bigger problem lies in the fact that so many journalists these days seem hell bent on taking information they gather from numerous sources (often Wikipedia, organisation web sites and LinkedIn) and just pasting it together in a way that they think makes sense. Context is lost. quotes appear uninformed and vapid. And in only a few lines the article managed to make me sound daft, give me a different job, include my employer's details (despite this having nothing to do with my employer) and dumb down the conversation we had to a banal au jus. This has consequences. I get a good ribbing and some eyebrows are raised. For the reader, they take away something only half-formed and that can then propagate. I guess this has always been the case with news media. It's not the first time I've been involved in a piece that ended up less than impressive.

Thankfully I did urge the guy to contact Nathaniel Vaughn Kelso which he obviously did and it can't be a bad thing that he and others get recognition.

And just as I thought things had died down someone on social media posted a link to the article clearly suggesting that I had said Null Island was "a place for people who can't use maps". I never said that. Neither did the article.

Lightweight reportage followed by Chinese whispers (that's the 'telephone game' for U.S. readers).

Silly season has arrived. Anyone fancy a chip?

Friday, 22 April 2016

Cartographic Cost of Open

The recent retirement of Kobe Bryant of the LA Lakers had the LA Times reveal a beautiful map of every shot he ever took - all 30,699 of them. It's a lovely piece of large scale mapping that sits at the intersecton of data art and information graphics. You really should see the live interactive map here because the screengrab below doesn't do it justice. That said, I'm sure you'll already have seen it. The LA Times also gave us a great 'how did we do it'.

My good friend Mike Gould this morning posted this:
My thoughts on this congealed over breakfast, spurred on by a twitter conversation I followed in the wake of the LA Times map on Bryant's shots. Mike's right in many respects - he's alluding to the idea that it's getting a little tedious seeing so many so-called re-inventions of maps.

You see, this sort of shot chart/map has been done before, most notably by Kirk Goldsberry who also mapped Bryant's shots back in 2013.

Plotting data points on a map is not a new phenomena that began with Kobe Bryant shot data but a few people pointed out the similarity between the LA Times version and Goldsberry's. There's no getting away from the fact they do look similar but - same dataset (although LA Times is more up-to-date), same court structure (hard to get away from though LA Times flipped the court) and same colours...well, any self respecting map-maker would inevitably use the Lakers' purple and gold colour scheme in their overall design.

So what? To my mind there's no copyright or Intellectual Property Right on a mapping technique. Yes, there's a lot of copyright associated with cartographic brands - because the style of a map or a map series often goes hand-in-hand with a long-term objective for brand recognition. Think of any major mapping agency such as SwissTopo, National Geographic, Ordnance Survey. Think London Underground. Think New York Times graphics. They are all very protective of their brand which is really just a function of the very particular style they have designed and honed over many years. Yet many other people use the same mapping data and make maps of the same places that all these mapping organisations do. That's what's happened in this era of open data. Mapping data has become democratised, often emancipated and made available to everyone, not just the big cartographic and media guns. Further, data feeds and all sorts of interesting datasets (like basketball shots by individual) are made available for free or at low cost. It brings tremendous access to the data and inevitably, a clamor to map it. It's therefore inevitable that similar designs will emerge.

But c'mon - the fact that one person makes a map of the data and then someone else does really shouldn't get people so upset because you can't have it both ways. All this free and open data does not come with a disclaimer that:

1. If you are the first to make a map with it you win and no-one else can
2. If you settle on a design that riffs off others then sure, give them a nod, but it's not obligatory

Importantly, you should probably be aware that you probably weren't the first anyway. The same thing has happened with the NYC taxi cab data. There are plenty of people doing very similar things. That's the cartographic price of open. We're getting a lot of maps shouting and competing for attention, all clamoring to be seen as original, distinct and the best.

This presents real tensions. I often get asked if you can create a particular map using Esri software and the answer is almost always yes BUT...and it's a big but...if another mapping company has an example of that type or style already (or someone who is a proponent of an alternative mapping platform has made one) then if I go and make one that looks similar guess who gets slated? For instance - making stacked chips on a map is neither new or difficult. Erwin Raisz was doing it by hand in the mid 1900s for example. I had a good friend make one in our University project atlass in 1991. If I go and make one now I don't get accused of copying Raisz...I get accused of copying a more recent viral version. This mindset of attributing originality and intellectual property to only recent versions of techniques is baffling and damaging. The fact you can use any number of different pieces of software to deploy a particular mapping technique is a good thing but please don't see that technique as belonging to one person or organisation over another.

I've had similar experiences in the past and, again, recently. I'd been playing with the Mars MOLA elevation data as a bit of a side project and then Chris Wesson drops his very elegant map - in the style of an Ordnance Survey map sheet. Now, Chris works at Ordnance Survey so he's entitled to use that design and it's an interesting take on how to process the data. Then Eleanor Lutz published a lovely hand-drawn map of part of Mars herself. And what of my map of Mars? - well, was I relegated to the third person to get their Mars map out? It depends when your starting point is.

Maps of Mars have been made ever since Giovanni Schiaparelli had a go in 1880. USGS has been publishing topographic maps of Mars for decades. Do a quick Google search for maps of Mars and you'll see that neither Chris, Eleanor or myself were the first though, to be fair, none of us has claimed to be. We just used the same data, did something different and hey presto - three more maps of Mars.

The crux is that if the data exists, people will map it. We really should stop being so precious about one map over another because if truth be told, pretty much nothing is actually that original any more. It's true that some maps bubble up and become internet stars and they are often seen as the version that people see as definitive. But it doesn't and shouldn't stop people from using the same data and even using some of the same ideas. Let me be clear - blatant rip-offs do exist and should be pointed out as such but there's often a fine line as I personally feel the LA Times map illustrates. Organisations and individuals have also developed very specific styles and these too should be seen as something worth protecting. But why would LA Times use triangles for the symbols and colour them in red? Makes no sense. It'd make a crap map. As long as they use circles and purple they run the risk of getting accused of some level of plagiarism.

Cartographic techniques are not copyrighted. I never see anyone reference Baron Pierre Charles Dupin in the footnotes of their choropleth maps, or countless weather map organisations as inspiration for the hideous rainbow colour palettes that seem to have become de facto in mapping weather. So - the LA Times need not reference Goldsberry's work or, indeed, John Snow as an early example of mapping discrete events in space using single symbols to see a pattern emerge (and that's not including the use of dots in demographic mapping going back to the early 1800s).

My data has brought a wealth of new maps to the canon. They build off the legacy of many that have gone before but hardly any are truly unique. If we are happy to support the notion that we want open data and open access to data we have to also be happy with the notion that cartographic techniques and their use are also to use and (as we often see), open to abuse.

Now go and search Google for Kobe Bryant shot'll see plenty more and also a load of hex-binned versions and so-called heat maps to boot. That's another story.

Finally - just a heads up...If I can find time, I'm going to try and make a map of some aspect of England's 1966 World Cup win as it's the 50th anniversary in July this year. I'm quite sure no-one else knows of this and no-one will either be thinking of making a map or of using the same data.

Tuesday, 12 April 2016


I had the pleasure of working with Mamata Akella when I first started at Esri. Mamata went on to work for the National Park Service and is now at CartoDB where she seems able to flex her design wings with thematics. This is fertile space in mapping in general and it seems never a week goes by without someone re-inventing a thematic mapping technique, occasionally with a new twist. Mamata's latest map caught my attention.

In response to her call for comments I hope she won't mind me using this blog as a space in which to offer my opinion and insight so here's a critique of the map above.

It's visually arresting. It's one of those maps you immediately stop and look at so it does a great job of getting people to pause and spend some time with it. That's probably the point so it's already done it's job. Because it lacks a title or any popups or marginalia one quickly gets lost though. As Mamata explains, it's a test and, no doubt, not designed to be used as a fully fleshed out project but it would be useful to include the basics.

It's the 2012 US election data. A well worn dataset that's just about exhausted most techniques. I spent some time with it myself a couple of years ago creating a gallery of various thematic map types. But with the 2016 election on the horizon many will be experimenting with new or modified techniques to prepare for that mapping extravaganza (me too...but you'll have to wait for that).

So what's going on in this map? Mamata calls it a 'modified cartogram'. Symbol size is total vote. Colour is the winner (red=republican, blue=democrat). Units are counties.

First off - I like the appearance and I like that it's in an equal area projection (Albers). It's eye-catching and somewhat different. I then quickly get uncomfortable with the function and how the data processing encodes meaning. Clearly the real geographic boundaries have been processed. My sense is a regular grid of rectangles has been used in which to bin the counties that fall within. That explains the regular grid and also the irregular number of symbols per location.

Geographical boundaries have been replaced by an abstract geography. It's referred to as a cartogram, likely because of this abstraction but a cartogram it is not. Cartograms distort space but they don't aggregate in an irregular fashion. Think Gastner-Newman, Dorling, Demers or a basic non-contiguous cartogram which all treat geography in different ways but which do not apply a binning technique as an interim step. Further, cartograms don't have overlaps. Mamata's symbols do overlap. It's therefore difficult to know how many counties are represented by each location and it's difficult to ascertain the distortion of the underlying geography which will inevitably be greater in areas with larger numbers of smaller counties. It's adding in a visual complexity that isn't necessary even though it gives a neat (as in regular - pleasing to the eye) looking final appearance.

I don't particularly like the way transparent overlaps on the symbols yield overlaps with darker shades - to me that visually implies 'more' yet is purely an artifact of symbol size bleeding into an adjacent symbol and not necessarily a function of geography at that place or overlapping geographies. Of course, when we're talking about mixing blues and reds it gets even more difficult to visually disentangle. That''s not a problem simply on this map though. I wrote about it before in regard to proportional symbol maps.

So it's a gridded proportional symbol map? Looks that way. Are symbols stacked? Possibly - in which case a lot of colour is missing due to occluded symbols which changes the ratio of blue:red colour across the map as a whole. If the data is really represented as rings then OK, we're seeing everything but it's also hard to determine why some symbols have more transparency applied than others (strength of vote?).

There's no labels which makes it difficult to describe the pattern verbally and causes even more problems if you don't actually know this is the USA. When you zoom in, the map refreshes with some very big changes in symbol size and larger white spaces so the structure we see for the whole is lost. This makes it hard to retain a mental image of pattern at one scale and compare it to that at another and we very quickly lose where we are on the map.

If it's a proportional symbol map then why not just use geography, even if you discount the boundaries and make a proportional symbol map?

I'll tell you why - they just ain't sexy enough in today's modern mapping landscape. So that's why Mamata experiments. It's why I experiment too. Sometimes we hit, sometimes we miss in our search for something just a little bit unique to develop cartography and showcase the tools and technology of our trade.

For my money this is a miss. I like the look but I think it complicates the subject matter and confuses the cognitive process of understanding the patterns in the data. For me, form should never outperform function. Cartography really is, at its very essence, that art and science of marrying form and function in harmony. You've got to get both right to make a good map.

Back to it being a cartogram - no. It isn't. But maybe Mamata's created a grid-O-gram?

Update: Inevitably, whenever I do one of these critiques I get called out for it being on a map made by someone who works somewhere that I don't. First, Mamata asked for comments. Second, I couldn't care less where she works and this IS NOT about the tech she used. None of my critiques are about the tech. It's about the cartography. Sure, tech affords opportunities or constraints but I don't care one bit about who uses what. This is not about scoring points. I don't publicly critique maps made by colleagues at the place I work because there are better mechanisms for me to use to try and effect change from within. And surely, if anyone thinks it's a good idea openly calling out your employer and those who you work with, you must work in an incredibly forgiving place. I do call co-workers maps out all the time using appropriate avenues. They critique mine too...often in very stark terms. Critique is good. Using different mechanisms to get the job done is important for cartography whomever you work for. So - don't get irate just because Mamata and I work at different companies. It's irrelevant. And yes, many maps I see made by friends, colleagues or whomever are truly awful and I tell them that. Silence in a public space can often be deafening.