Chart deconstruction: Mountain Range Histogram

One of my favorite things, especially for my personal work on Tableau public, is to come up with unique ways to use out-of-the-box features. I think the best way to describe it is ‘visual hacks’. No crazy geometry involved. Only factory parts.

This post is part design process and part how to, for a recent visual hack chart that I made. This was created for my viz collaboration with the completely and ridiculously amazing Chris DeMartini.

I call this chart the Mountain Range Histogram. You can see it at the top of the viz:

Grounded

Design Process

For the Grounded viz, Chris and I had both agreed pretty early that the main chart would need to show the history of the jump distances. But, we would also need some additional charts to add details and context. So for this mountain range chart, I started out wanting to show a histogram of jump distances.

There were a few reasons why:

  • Bins are an awesome way to categorize quantitative measures
  • Needed to show the range of distances but also which ones were most common
  • Needed to show how those ranges and frequencies changed over the years
  • Did I mention how awesome bins are?

I started out with just a basic histogram, but then I noticed that there were some interesting shifts over the years. Some years showed huge gains for all jumpers. And some years showed decreased distances across the board.

That made me realize it might be most interesting to show the totals per bin for each year, instead of a total for all years.

It’s no secret that I’m a big fan of dot plots, so of course that where I went with my first iteration!

Histogram dot plot

That had some potential. There was enough variation in circle size to make it interesting. But what if…. We made it into (fake) semicircles?

Arcs histogram

I thought this turned out quite beautiful. And with the color opacity set extremely low made the semi-circles look almost like arcs. So it could go nicely with the jump chart.

But then I started thinking.

Really thinking.

Was there some sort of visual metaphor that made more sense for the specific topic of this viz? Mountains! Would it be possible to make it look like mountain?

Mountains

Ok, so not quite as easy as just drag and drop. But with just a little bit of tweaking to the Y axis, and a little clean up…. we have a mountain range histogram!

Mountain range histogram

I can’t say that there are a huge amount of use cases for this chart – it worked perfectly for telling this particular story. But I think it’s a great example of how you can get hacky with even the simplest default options in Tableau, like the triangle shape mark.

Just how simple, you ask?

How to create the mountain range histogram

  1. First, you need a measure that you can bin. In this case, I created a bin of jump distance.
  2. Put that measure (distance) on the columns shelf. Set the aggregation to average
  3. Drag the bin field to the details mark. Optionally, also drag on the year field to the detail. This creates a mark for each year and bin
  4. Now put jumps (count of jumps) on the size mark
  5. Change the mark type to shape, and choose the filled triangle
  6. Now we need to fix where the Y axis starts, so the triangles look like actual mountains. First, create a 1.0 field, and drop it on the rows. Set the aggregation to minimum
  7. Edit the axis start and end. I set mine to start just a tiny bit below 1. This just cuts off a little bit of the base of the triangles

And that’s it!

Of course if you want to check it out in more detail, you can download the Grounded workbook from Tableau public.

 

 

 

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