If you’ve ever built a filled map in Tableau where some of the areas are too small to stand out or label effectively, then you’ve probably come across hex maps as a solution. A hex map means that each area is the same size, regardless of the actual relative sizes.
For example, note how the Nelson (NSN) region in this filled map of New Zealand is relatively small compared to other regions, and hence hard to see and label:
Whereas in this hex map version Nelson (NSN) is the same size as the other regions:
In extreme cases the relative size and colour of the border compared to the area can even skew people’s perception of the colour. Also if you want to go a step further and show how data has changed over time (or some other dimension) per area, then you may have heard of tile maps as an option:
But how do you build these in Tableau?
Tile Map Template
I tend to start with a tile map design as it’s easier to visualise in a grid! I find the map I want to reproduce and then plot the areas on a grid in Excel:
Note: Because you’re scaling up small areas and reducing to tiles it won’t be possible to faithfully reproduce the geography. What you’re aiming for is a rough approximation that still looks like the overall geographical area you’re representing, whilst allowing you to show each area at the same size. For example, in New Zealand the West Coast (13 In the grid above) should stretch up further, and I compromise on whether Tasman (10 in the grid above) is south or west of Nelson (11).
Once I’m happy with my grid I create a sheet that has the list of areas (regions in this example) along with the coordinates from the grid:
Using this data I can plot the tiles in Tableau. Dragging X to Columns and Y to rows, I get a mark/area per region. And it is laid out as per the design in Excel:
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Tile Map Example
Linking the tile map data set to another data set allows me to produce a set of small multiple charts arranged as per the tile map design. Let’s take a look!
First up define the data source:
Here I’m relating a data set that has NZ population by region and year, to the list of regions and their coordinates. I’ve ended up using a relationship calculation as part of the join on region name to replace “Wanganui” with “Whanganui”, as the two data sets use different spellings.
From here building the view is like the template, dragging X onto Columns and Y onto rows. But this time I also drag Year onto Columns and the measure I want to plot onto Rows (in this case the % change in population since an index year I’ve chosen). This gives me a separate chart of % change by year for each region, in its grid location (Southland in 1, 8 for example):
Note: in this example I’ve also created a fake measure typed straight onto Rows – AVG(0.5) – on a dual synchronized axis. I’m using this with a blank custom shape as a mark that I can attach a region code label to for the first year on each tile. There is also a reference band from -0.5 to the window max of my fake measure (-50% to +50%) on this axis to provide a light grey background where we have data.
When I hide each header, apply some formatting (blue background, grid lines turned off), and include on a dashboard the result is:
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Hex Map Template & Example
A hex map is on one hand simpler, and on the other more complex. It’s simpler – in my opinion – because it doesn’t suit including a chart within each hexagon (unlike the tile map). But it’s more complex in that the hexagons aren’t on a simple grid. Let’s take Nelson (NSN), Marlborough (MBH) and Tasman (TAS) in the example below:
MBH is to the east of NSN and so is +1 across on the X axis.
And in my grid system it’s also +1 down on the Y axis, but it actually starts halfway down NSN and a little indented, so that the hexagons tessellate.
TAS is completely below NSN and so is +2 down in my grid system.
I work this out by trial and error by adapting the tile map coordinates to suit a hex map. Ending up with a list of regions with X and Y coordinates again:
Creating the view is also very similar – dragging X to Columns and Y to rows, hiding headers for the X and Y pills, formatting the colour and removing things like grid lines. But this time I use a custom hexagon shape. For the example below I’ve also used a data source similar to the tile map example above where I relate the hexmap coordinates Excel sheet to the regional data I want to show.
Note: in the screenshot above I’ve sized my window and adjusted the shape size in Tableau so that the hexagons are nicely aligned (same space on each side). This is quite fiddly, and you’ll have to play around to get it right when including your map on a dashboard. Including on a dashboard is a good way to retain control over the sizing. An alternative is to draw a polygon where you have much more control over spacing but that is outside of the scope of this blog!
The finished result on a dashboard:
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Feel free to use the templateS
You’re very welcome to use these templates in your own work if they’re helpful.
The workbook is available on Tableau Public (templates and examples):
https://public.tableau.com/app/profile/steve7374/viz/NZTileandHexMaps/CONTENTS
And the Excel grid data on the Tableau Forums:
https://community.tableau.com/s/news/a0A8b00002HfQecEAF/new-zealand-tile-and-hex-map-templates
I’ll be following this post up with more APAC tile and hex maps. If you’ve got any requests let me know. I’d also love to explore a way to generate the tile and hex grids from actual the original region coordinates or shapes … but that is a much more complex problem!