Peter Fakan: How I Created this Isometric Map in Tableau

 

I’m excited to have another fellow Forums Ambassador, Peter Fakan, join us this week for a guest blog. When he first posted this beautiful map, I immediately messaged him and asked “How did you do that?” and he graciously explained his whole process. Not only is the viz itself very cool, but the techniques Peter used are quite useful in a variety of other areas. So, of course, I asked him to join us for a guest blog!

 

Peter is a Tableau Developer in the Australian Government’s Department of Veterans’ Affairs. As mentioned above, Peter is also a Tableau Forums Ambassador; he has a deep knowledge of Tableau and is one of the top contributors on the Tableau Community Forums. You can get in touch with Peter on the forums.

 

The Viz

I recently saw a data visualization that projected a map using an isometric view. After seeing this, it struck me that I hadn’t seen anything like this done in Tableau. I also thought it might help me with the eternal problem of managing 5 data points on the eastern side of Australia, versus the one on the Western side. To add a bit of complexity, the Australian Capital Territory is nested completely within one of the states. So, I decided to see if I could actually create something like this in Tableau. With a bit of help from Airtasker.com, I was able to do just that.

 

Use Case

Before I show you how I created this, let’s talk about the use case. Generally speaking, I wouldn’t recommend this for mainstream visualisations as the overhead to create it puts it in the category where you would want a professional developer maintaining it. That said, I think it has the essence or “oomph” you might be looking for inside a flagship visualisation where you are looking for that additional “pop” to make your viz stand out. Plus, it’s fun to try to stretch Tableau to see if we can do something a bit out of the ordinary.

 

Map Image and Data Prep

First things first, I needed to obtain an image using this projection. Fortunately for me, this is where Airtasker.com came in. Airtasker is a site where you can post any type of task you need and find a qualified person to do it for you (it’s similar to sites like fiverr.com, which I know Ken & Kevin have leveraged in the past). I was lucky to find a great graphics design student who whipped up some quick comic-style polygon images of Australia for me. I ended up getting three different variations created as we were discussing future uses where we might want the whole landmass, the states broken apart, and then the states and territories coloured.

 

The graphic designer did more than just draw the pictures for me. Collaborating with the designer really helped me to plan out what I wanted to do with the viz, including helping me to realize that I had a congestion problem on the east coast.

 

To address this problem, we realized that we could rotate the map to the left in order to create some extra space on the east coast, allowing us more space to label the different geographic locations. This, of course, is a technique you could use with more “standard” maps as well.

 

 

In the end, we had the following images:

 

Next, I created polygons using the Custom Background Image Studio utility from Interworks, which allows you to create a data set of points by simply clicking/tracing on an image (Ken actually used this in his blog on creating a social distancing floor plan).

 

I ended up with something similar to the above, though I tweaked it a bit and forgot to capture a screenshot of the final version. The Interworks utility then allows you to extract the data points as either an Excel or csv file which can easily be loaded into Tableau and blended with other data.

 

Note: When using the utility, be sure to capture the values in the “Scale” section as we’ll need these when we get to Tableau.

 

I also created some transparent callout bubbles that I could use to label each geographic area on the viz. You can create these pretty easily using PowerPoint.

 

Note: If you dig into you the final viz, you’ll see that I actually went a slightly different direction for these shapes.

 

Tableau

With data preparation complete, now it was time to hit Tableau. First, connect to the data set you generated in the previous step. This will give you cartesian coordinates (x, y pairs) needed to draw the polygons. You will need to identify each polygon as one of the states. You could do that directly in the data file, if you like, but I chose to just create a calculated field:

 

But this data set only gives us the coordinates for each state—you’ll also need another data set for the actual data you’ll be visualizing. I chose to use the APAC Superstore data set and brought it in as a new data source. I then set up a blend relationship based on State.

 

Now, on a new sheet, we place AVG(X) on the columns shelf and AVG(Y) on the rows shelf, drag Point ID to the path card, and add State to the detail card.

 

Next, we’ll add the image as a background map by selecting Map > Background Images > <Your Data Source Name>. Set the X and Y ranges to match the “Scale” we captured when using the Interworks tool.

 

You’ll now have something like this:

 

As you can see, our polygon is overlapping the background image. We still want that polygon there so we can interact with it. To correct this, just change the opacity to 0%. Or, as an alternative, use a transparent colour. You’ll now see the full background map, but will still be able to interact with the polygons.

On my final viz, I added labels so you can see the value of the rotation, which frees up space on the right side. Here’s my final viz. Click on the image to see the interactive version:

Closing

Again, I wouldn’t recommend this for mainstream visualisations, but I think it has the essence or oomph you might be looking for inside a flagship visualisation. I also believe some of the techniques used here could be of value in other use cases. I had a lot of fun with this build and am excited to see where other developers might take the concept. Thanks for reading!

 

Peter Fakan

June 27, 2022