Wednesday, 25 April 2018

A new map in prospect

We took @wisley_dog to one of his favourite local parks the other day. Prospect Park in Redlands is a lovely spot that sits a little up the hill in south Redlands offering spectacular views across the San Bernardino valley to the mountains beyond. It's a mix of trails, orange groves, places to picnic and also houses an outdoor amphitheatre. It's also next to Kimberly Crest House - one of Redlands historic houses. At 11 acres it's not a large park.

Like many, we parked on Cajon St and entered the park by its North-East access points. There's a shady picnic spot and, as I found, a new information board which houses a new map of the park. Here it is, measuring about 3ft wide:


That's a lot of map for a small park. It kinda ruined my walk. It likely ruined Linda and Wisley's walk too as I bent their ear about the map and its problems. So let me bend your ear too and, hopefully, in the process, show you how to critique a map.

On the face of it it looks nice enough but as with anything that's dressed nicely it can often deceive. So let's deconstruct it a little and have a conversation about some of the cartographic and design choices.

The information board is located on the North-East edge of the park. You look at it facing South-West. Yet the map is oriented with North-West at the top to align Highland Ave with the top edge of the paper. This makes absolutely no sense. Fundamentally, the map is oriented incorrectly. These sort of in situ maps need to be oriented so the map is laid out as you look at the park in front of you. This map should have Cajon St at the foot of the sheet and, as you look (and wander) beyond the map you can then easily process the lefts, rights and other locations of points of interest in the park. Rotate the map and you get this which is far more useful from that location:


This is an all too familiar problem of maps on information boards like this. It simply needs the people who commission the map and those making it to have a conversation about where it's going to be displayed. It means if it's to be displayed at several locations it should be rotated accordingly but that's not difficult if you use a GIS and it's data-driven. It's also not difficult with some forward thinking as this other Redlands park map shows. The Caroline Park map is on a board on the south edge of the park. North is top and you stand looking at the map, looking northwards. Perfect. It's also a beautifully illustrated map that shows you the function of different parts of the park as well as the flora and fauna you may see.



Back to the Prospect Park map. Orientation is not the only problem. The labeling is awful because you have difficulty reading it.


Simply overprinting black text (in boring Arial) over the background is never going to work. There's so many ways of improving this. Masks, Halos, Shadows. Anything! And there's leader lines everywhere. they're unnecessary.



There's so much space on the map which makes should make lettering it an absolute joy compared to most maps. And as far as the overlooks are concerned, a symbol might be more useful and that would obviate the need for a typographic element and three ugly leader lines altogether.

So...overlook. That tells you something. It means that there's some elevation throughout the park. Yet the map displays no information to warn the casual visitor that there nearly a 100ft elevation gain between Cajon St and the highest point. A vantage point that then allows such beautiful vistas towards the San Gabriel and San Bernardino mountains (and the San Andreas Fault but I try to ignore that most of the time). OK, but there's a network of nicely paved paths right? They're all shaded grey so they're all the same?

Imagine you're a wheelchair user or struggle with walking up a moderate incline. You'd not only be frustrated that the map shows no detail of the elevation gain but, worse, many of the trails are nothing more than dirt and gravel making them almost impossible to access for some people.

By making all the paths the same symbol type the map infers they are the same. Yes, you can drive up to the parking lot at the top via Prospect Drive but you can't take your car anywhere else. You can't similarly access it from the other apparent entrance on Cajon St either. the map might not need detailed contours other other ways to show elevation but showing how elevation changes along the trails would, at the very least, be an extremely helpful piece of information.

And what of the parking to the left of the map that you can access via Highland Ave? Well, technically, you have to go through the entrance to Kimberly Crest house to get there and that has a gate that is locked at times when the adjacent park is open. Useful information, particularly so you don't get locked inside with no way out. In fact, that car park is not really part of Prospect Park at all. It's the access to Kimberley Crest House and Prospect Court as this OpenStreetMap map helpfully symbolises by specifically not including it in the green that designates the park boundary.



Take a look at the OSM map again - it shows one route into the park for cars to get to the central parking lot. It shows clearly how you access it via Prospect Drive. It shows other trails inside the park differently to distinguish their use. But while we're at, it there is an error on this map too. If you access Prospect Drive from Highland Ave you cannot drive through and round the bottom edge of the park and into the Prospect Park lot that way. There's a chain across the road to prevent access. And neither OSM or the new Prospect Park map has the new footpath included between the Kimberley Crest car park and Highland Ave.

Zoom in to the OSM map. See those water fountains? Redlands can get kinda hot. Water fountains are important for dogs and humans alike. They should be on the map. The Prospect Park map has restrooms (labelled - maybe another case for a symbol?) but not water fountains. Makes the map a little partial with basic information.

And back to the map's background. At first glance the Prospect Park map appears to be a hand-drawn and painted map. I think it's based off some form of digital data (possibly even just traced off imagery). It looks OK but it could be so much better. Each orange tree gets a uniform symbol. A bit of rotation on each would make the groves look more organic and 'real'. And what about all the other vegetation? There's palms, giant mature specimen trees, a bamboo forest, seating and grassy areas to name a few major parkland types of ground cover. yet pretty much everything other than orange trees and the palms along Cajon St gets the same smudgy fill. This could have been so much more exciting with other tree species canopies or symbology.

There's also a small creek than runs between the picnic area beside Cajon St and the park beyond. Why wouldn't you mark that? It has 6ft walls despite not always having much water in it. It's hard to miss in reality yet the map makes no mention of it. It's a prominent feature yet all the map has to indicate anything is a bridge label next to a cross-hatched rectangle that is presumably supposed to represent the bridge itself. A bridge over what?

Possibly a spelling mistake too...lower left 'Orange trees on Terrance'. I think they mean 'terrace' though I can't be absolutely sure. I've never seen Terrance there. I don't know anyone named Terrance.

The north point thing seems to be a small apology wandering aimlessly in a vast space because there was a space and to cap off the entire map the title and credit lines are in Comic Sans - that font that every map-maker loves to hate. Is this a subtle bit of carto-trolling? Could be. Could just be a pointless use of Comic Sans that makes no sense on a map that otherwise uses Arial. And why on earth would set the title in horizontal letters aligned vertically? Use Comic Sans with purpose. Reserve it for the uses it was designed for (children, comics and, latterly, to support those with dyslexia). It has no place on an information map like this - in the same way Papyrus has no place on restaurant menus.

So...what to do. Well, I've had a moan. I've justified my thoughts based on what I know about cartography. I tell you what, I'll make another version (for free) and offer it to the City of Redlands Parks Division. I'll post back when it's done and invite anyone and everyone to critique my map. In the meantime, you'll find me at Caroline Park where I hope they're not planning to update the current map with a similarly weak replacement.

Thursday, 29 March 2018

In praise of insets

Sky News reports on the Scottish politician Tavish Scott (real name) as he proposes a ban on maps that use an inset to show Shetland. Utter nonsense.

His reasoning is that the 'islands should be in the right place on the map' and 'to ensure that in future that government publications and documents do reflect the reality of Scotland in terms of its geography, and not something that fits neatly on an A4 sheet of paper.'

Well let's just break down (sorry, I mean utterly destroy) his preposterous statements. Shetland (The Shetland Isles) is a part of Scotland. It's also part of Great Britain...and the British Isles... and the United Kingdom (and at the time of writing at least, Europe). The following usefully clarifies the terminology:



So in that sense it has a rightful place on any map of which any of those jurisdictions is the focus.

If you're not aware of where Shetland is in the world then this should help (map to scale, UK National Grid):



In simple geographical terms Shetland is approximately 130 miles from mainland Scotland though it's also on the same line of latitude as Bergen on the west coast of Norway at a distance of 200 miles. That's where it sits. At a nice northerly 60° 9' 11" N and 1° 8' 58" W. We can argue all you like whether it should be part of Scotland or, perhaps, a bit of waste left over from Slartibartfast's design of the Norwegian coastline but for now, it gets put on maps of Scotland and any other that includes Scotland. And that makes it a pain in the arse for cartographers.

By the way, did anyone spot I deleted France from the map above? Guess that'd annoy the French too but whatever, I doubt the scots or Scott cares much about that little cartographic editorial decision.

Anyway, as the scot, Scott, says, many maps are made on A4 (or any A series piece of paper where the length and width are in the same proportion). So here's the above map proportioned as A4:



The area outside the yellow line is superfluous to the map as the Republic of Ireland is irrelevant on many maps that show thematic data for Great Britain and Northern Ireland (or UK etc). So as a rough estimate the page only uses approximately 60% of its overall space to show the mapped content.

Put another way, we need a fifth of the entire page (above the green line) just to get Shetland on. That's Shetland, population 22,000. Or, in geographical terms, an island that is 566 sq miles which is 8x larger than the City of Glasgow but which has 27x fewer people. So you're making a decision to allow geography to not only influence the design but take an inordinately exaggerated status simply by virtue of position.

Now, admittedly there'e lots of lovely space for titles and legends and all the other crap we put on a map but, nevertheless, it's wasteful. But that's what you'd have to do if you want Shetland on the map, on that proportion of paper, in its correct geographical position. Alternatively, as Scott bemoans, cartographers will often use an inset and you'd end up with a map like this:



This fits the map to the paper (not the paper to the map). And there's far less wasteful space. Far less prominence to unpopulated swathes of water. And yet Shetland gets its own little special place on the map, with the addition of a neat border that clearly demarcates it. Often, Shetland is even exaggerated in scale to make the inset worthwhile. I bet you didn't notice but in the example above Shetland is about 25% bigger than it really is. So, if Scott wants Shetland back in its proper geographical location then he can have it reduced back to its real size too.

Insets are a neat solution and one that has served print mapping well for centuries. It's also a solution that people understand. You could add a small arrow and distance marker to point to where the inset exists in reality. Many even use a marked graticule to show clearly the lines of latitude and longitude that apply to the inset to make it clear that it differs from that of the main map. Even the Sky News article showed an historical example that clearly uses this technique (and note how exaggerated in size Shetland is on this too):


There's other considerations...

Returning to the City of Glasgow. In fact, any relatively populous place. They suffer horrendously on any maps of thematic data because large areas, perhaps relatively uninhabited or sparsely populated take visual prominence. Scotland is a great example. It's total population is around 5.3 million yet 1 million of them live in Glasgow and Edinburgh. Their population densities are far more than the far greater share of Scottish land, including Shetland. So why give such visual prominence to sparsely populated areas?

Insets are not just used to move geographically awkward places. They are commonly used to create larger scale versions of the map for smaller, yet more densely populated places. Often they are positioned over sparsely populated land to use space wisely. I'm guessing Scott would have an objection to an inset that, to his mind, would exaggerate the geographical importance of Glasgow compared to Shetland. Yet...in population terms it's a place of massively greater importance so one could argue it deserves greater relative visual prominence on the map. Many maps are about people, not geography.

In addition to moving Shetland south to make better use of map space, you could very well argue that you should use a cartogram to give far better relative visual prominence to the places where more people live and work. Now that will utterly delight Scott as it completely distorts geography. Not only could you have Shetland moved, but squished to an almost unrecognisable shape. Here you go Tavish...enjoy this beauty of population totals morphing geography (courtesy: worldmapper.org):


Whatever your view of insets (and Scott's is incorrect), there's so many valuable uses for them that counter the problems of geography making it awkward to make maps. Generations of cartographers have come up with novel solutions to many, if not all, of these dilemmas about what to show, where and how. And if the map has an overarching location map showing everything in its correct position then there can be absolutely no confusion whatsoever.

I would guess Scott would equally be horrified if Shetland was seen poking outside the graticule or neatline on an atlas page too - another common way in which maps break the rules of either geography or design in a creative way to simplify and communicate. He'd be delighted by this classic Times Atlas of the World page showing Shetland in its correct position as part of The British Isles but horrors of horrors...Rockall (also a part of Scotland so has equal rights on a map based on Scott's nonsense...but ignore the more northerly Faroe Islands, not part of Scotland) slips off the left edge:



And what of digital maps? Scott seems to be stuck in the age of print cartography because insets are rarely, if ever, a requirement in digital cartography. Everywhere exists where it is. The map is slippy and you can pan and zoom to your heart's content. Want to see a densely populated area? Zoom right on in. In fact, whisper it quietly in case Scott is listening but...if he uses the standard Web Mercator web map he not only gets Shetland in its rightful position AND it's also exaggerated in size compared to the southerly latitudes of mainland England by virtue of the projection. Now isn't that the map he really wants?

Wednesday, 7 March 2018

Dotty election map

Well that escalated quickly...

While I've been working on the forthcoming book and mooc I've been doing some data wrangling in the background at work. For the 2012 Presidential election I made a gallery of maps that illustrated diverse styles of cartography along with some comments on the map types. Each map can tell a different story of the election. I've been in the process of updating this with a new gallery of the 2016 election results (currently around ten maps but more to come) and I got to the tricky one - the dasymetric dot density map. It requires quite a bit of manipulation of data so here is the map, and in this blog I'll explain a little of the process.



In 2012 I made a similar map for the Obama/Romney election. It was a product of the web mapping technology of the time. Made using ArcMap (full disclosure for those who don't know I work for Esri - who make ArcGIS). At the smallest scale 1 dot = 1,000 votes. At the largest, 1 dot = 10 votes and if you printed the map out it would be as large as a football field. It took 3 months to cajole the largest scale map onto the web!!! I wanted to update the map and the four years that have intervened have brought new software capabilities. For 2012 I had to generate up to 12 million points and position them. Now, using ArcGIS Pro I can use the dot density renderer and let the software take the strain and if I were going all out then why not try and make a map where 1 dot = 1 vote. So, for me, the map is a technical challenge. Part of what I do at work to push the software to see what it is capable of, to test it and to show others what capabilities it affords.

So how to make the map? Well, it's a product of a number of decisions, each one of which propagates into the map. I'll be doing a proper write-up on the ArcGIS blog in due course but, in summary, a dasymetric map takes data held at one spatial unit (in this case counties) and reapportions it to different (usually smaller) areas. It uses a technique developed by the late Waldo Tobler called pycnophylactic reallocation modellingThose different areas are, broadly, urban. The point of the map is to show where people live and vote rather than simply painting an entire county with a colour which creates a map that often misleads [Waldo sadly passed away recently and I was running the model when I heard of his death a couple of weeks ago. I met him a few times and his legacy to computational geography and cartography is immense].

I used the National Land Cover Database to extract urban areas. It's a raster dataset at 30m resolution. I used the impervious surface categories and created a polygon dataset with three classes, broadly dense urban, urban, and rural. I then did some data wrangling in ArcGIS Pro (more of that in a different blog) to reapportion the Democrat and Republican total votes at county level into the new polygons. There's some weighting involved so the dense urban polygons get (in total) 50% of the data. The urban get 35% of the data and the rural polygons get 15% of the data. Then I got the dot density renderer in ArcGIS Pro to draw the dots, one for each vote resulting in a map with nearly 130 million dots.

The result is a map that pushes the data into areas where people actually live. It leaves areas where no-one lives devoid of data. It reveals the structure of the US population surface. Most maps that take a dasymetric approach will all end up like this but I think there's value in the approach. To me it presents a better visual comparison of the amount of red and blue that the standard county level map that maps geography, not people, and overemphasises relatively sparsely populated large geographical areas.

So the map I saw on my desktop late Tuesday afternoon took 35 minutes to draw. Technical challenge achieved. ArcGIS Pro nailed it. This is a map that I couldn't have made in the previous election cycle. I was excited and so I took a quick screengrab, sent out a tweet and went home to walk Wisley the dog.

And that, I thought, was that. I'd put the map on the backburner and return to doing layout reviews for the book and doing last-minute work on the mooc over the next couple of weeks. But then something unexpected happened. My phone started pinging. Slowly at first but then a little more during the evening as people began to see the map on Twitter and like or re-tweet it. That's nice, I thought. I went to bed. Wednesday morning I woke to a relative avalanche of likes and retweets. I spent the day in Palm Springs at our Developer Summit and my phone never stopped. By the end of the day it had received around 3,000 likes and had been retweeted 2,000 times. I'm writing this Thursday morning and it's currently at 7,000 likes and a little over 3,000 retweets. The side-effect of this 15 minutes of map fame is I've picked up an extra 1,000 followers (25% increase) on my nearly 10 year old Twitter habit.

But there's a problem. The screengrab was quick and dirty and while there have been many and varied comments on the 'map' it's by no means the finished article. I want to create a hi-res version and also make a web map like the 2012 version. I don't have time to do this in the next couple of weeks but it will happen. But be assured, I am aware of a number of issues. Some have already spotted them and commented.

The symbols - I chose a very default red and blue. Each dot has 90% transparency so overlapping dots at this scale will undoubtedly coalesce into clumps. The impression will appear to bleed across the map. I need to tweak the colours (less saturated) and adjust the transparency to get a better effect. I will also likely do what I did for the 2012 map and classify the data so that at small scales 1 dot = 100 or 1,000 etc. To remove visual 'noise' at those scales. I'll also check for too many overlaps and overprinting. I actually think there's a problem in some areas with blue dots overprinting red. There should be more mixing and more purple. And no, there's no yellow dots. The map only displays Democrat and Republican votes in what remains, effectively, a binary voting outcome.

The data - it's county data, reapportioned. Dot maps convey a positioning that is a function of the processing, not where people actually live or vote. Dots are positioned randomly. Some have, quite reasonably, interpreted the map as showing where votes are and this is a fundamental drawback of the approach. No personal information is in the map at all. I also need to double-check a few areas where people have pointed out apparent anomalies in the map, compared to their personal knowledge of the areas. There may be errors. I need to check. That said, it's a function of the way I've used the NLCD so that data is the basis for reapportionment.

The geography - yes, I hold my hand up. There's no Alaska or Hawaii. I apologise. I'm not sure I'll go back as it requires doing some movement of those states to position them around the lower 48 and put them back in. It's easy but a non-trivial task when you're working in a GIS but I'll think about it. I understand this is unpalatable for some and I accept that criticism.

The interpretations - many have offered some fascinating insights into the gaps and the patterns through Twitter replies. I'll be going through these more carefully when the hullabaloo dies down and teasing out some. But more than anything I've been blown away by the nice things that have been said about the map. It shows the election result in a different way. It tells a different story. One of my favourite responses was this by Thomas de Beus...a lovely mashup and play on the classic photo of Trump's preferred view of the data to hang on the wall of the White House by Trey Yingst.


And this is the point of making a map like this. It presents the SAME data in a different way. It leads to different insights, different interpretations and a different perception. Neither of the above are right or wrong. They are different. Of course, we all have out own view on which serves our needs and which we prefer but that's for us as individuals.

My only regret is that I excitedly tweeted a rough version. I should have waited until I made the map properly. I'll do that but I suspect this is my one viral 15 minutes of fame and I regret it doesn't reflect the quality I know the final version will exhibit. A finished map likely won't get the same traction but we'll see. At the very least it has ignited a discussion. It brings different cartographic eyes to the dataset. Will it ever be hung in the White House? Unlikely.

Thanks for your interest and comments thus far!
Ken

Hurriedly written from a hotel in Palm Springs during which time the map's had many more likes, 11 more mentions and I've picked up another 86 followers. I can only apologise to them when they realise I tweet just as much about beer and football as I do about maps.

Update: There's now a web map which shows the data at 6 scales in much more detail than the screengrab above. Check it out here.






Sunday, 31 December 2017

Favourite maps from 2017

I've been a little busy writing my book this year so blog posts have been a bit thin on the ground. It was only as I was packing up for a short Christmas vacation that I realised I hadn't even compiled my list of favourite maps from the year. So, with some of the world already embarking on 2018 here's a selection of maps that piqued my interest in 2017...in no particular order.

Trump's World by Phoebe McLean (age 15)
There probably isn't a better summary of the world in 2017 than this lovely hand-drawn map which won an ICA Children's map competition award


Planet Brewdog by Craig Fisher
It's just a map of Brewdog locations but it's massive and a perfect way to fill up an otherwise plain wall in a modern industrial brewery facility. Here, in the Columbus OH tap room.


Winter Map of Montana by Kevin Nelstead
I particularly like the halos on the white labels :-)


Tactile Atlas of Switzerland by Anna Vetter
Beautifully produced atlas for the blind and partially sighted using raised printing.



Cinemaps by Andrew Degraff
Stunning axonometric maps of over 30 films charting major plot lines and characters as they move through the film's landscape.


The new Swiss World Atlas by the Institute of Cartography and GeoInformation at ETH Zurich
A stunningly beautiful, rich and detailed atlas for secondary school children...actually, for anyone!


Blue and White Dream by anon (China)
Making a map with only a single hue is hard. This is visually stunning, especially set within a large Chinese wall hanging. Apologies, I don't know who created it.


Where the Animals Go by James Cheshire and Oliver Uberti
OK, so the UK version was published in 2016 but the American version was definitely published in 2017 and therefore qualifies. After the success of London: The Information Capital, James and Oliver hit gold again with this award-winning atlas of over 50 great maps plotting animal movement.



San Diego Emoji map by Warren Vick and Europa Technologies
Using gridded emoji is a great idea for a one-off map.


Fifty years of cyclone paths inside the Philippines by David Garcia
Just the lines drawn by the data but revealing the shape of the islands and, with it, the scale of the phenomena.


World Happiness by National Geographic Magazine
I'm a sucker for a multivariate Dorling cartogram Chernoff Face combo.



Lights On and Lights Out by John Nelson
Simple idea mapping the difference between NASA's 2012 and 2017 Earth at Night imagery. Exquisitely rendered.

The best places to see the eclipse by Josh Stevens and NASA
The use of clouds to show, err, the likelihood of cloudcover (and the inverse, clear skies) for the 2017 Solar Eclipse. Simple. Effective.



The Melting of Antarctica by Lauren Tierney
Stunning spread in National Geographic. Great composition and use of angle and projection to tell this story.



U.S. Airport ID requirements by The Washington Post
Neat, interactive use of the gridded cartogram


Dirk's Lego World map by Dirk
Because...maps AND Lego!!!

 
Hand-stitched London Underground by Tasha Wade
Gifted to me. Unique. One-of-a-kind. Thank you :-)



Trump's Ties by Kenneth Field
It's my list so here's my effort...I still quite like it. Won the Society of Cartographers Wallis Award too :-)