Flowing data posted nice and clear instructions on how to make bubble charts using R. It’s a great post, and I thought it would be a good thing to show how to create the same chart in Tableau. Readers can compare and contrast the ease of each. Let me know your thoughts in the comments below. Here’s the end result using Tableau:
You only need five Dimensions/Measures on the worksheet to make the view look the same as the one on Flowing Data. I added Colour to State in order to create the highlighting option in the dashboard above. Is this cheating – it’s 6 drag and drops – is that 6 separate steps? 🙂
Step 4: Clean up!
I prettified it a bit by changing the Mark borders and putting it into a well-proportioned dashboard.
The whole process took me 15 minutes. Once your up to speed with Tableau, you can get to work at lightning speeds.
Flowing Data’s post started off by mentioning Hans Rosling and the Gapminder project. Watch this space for more on Gapminder and Tableau….
This is the third post on simple tricks that are available in version 6. This one represents a common request we get. The client says “I want to compare the performance of x against everyone else.” What is x? Well, it could be Customers, Departments, Countries, anything.
The drop-down filter is a parameter control, in this example showing every State in the Coffee Chain connection. The Tableau devs have made it easy to create a parameter containing every member of a Dimension. Right-click on the State Dimension, and choose Create Parameter…:
That’s your parameter list created – show the parameter control on your worksheet by right-clicking on the parameter and choosing Show parameter control.
Next up we create a calculated field to return either the State selected in the parameter, or all the others. This is essentially a dynamic Group, with one lone member of the Dimension, and everyone lumped together in the “Other” category. In this case, you can call the “Other” category anything you want. Here’s the calculated field:
This is the field you drop onto your worksheet. Whichever shelf it is on, it will only show two members: the State selected in the Parameter, and everyone else lumped together.
This uses sheet tabs to create an “About this viz” tab. It is good practise to credit data sources and date your vizualisation. The About Box allows you to do this. I’ve used parameters to store the hyperlinks, and dropped them onto worksheets embedded into the “About this viz” dashboard.
Prior to v6, the choice was either to omit the credits, or squeeze them into your dashboard somehwere. No more!
One can always expect visually attractive stuff from David McCandless on his Information is Beautiful blog. Sometimes though, the visual displays potentially confuse viewers. Today’s great post on Wikipedia Banner Tests is an example. Representing the size of donations using a square is pretty, for sure. However, we tend to perceive the relationship of one area to another pretty badly. A linear representation is more effective:
Think back to David’s orginal squares view – would you really have guessed that the Jimmy Appeal raised fifteen times much cash? If so, you’re one of the few – most people would have said it was around 8-10 times larger. The linear view above makes that difference much more clear.
There’s also some interactivity on my view – you can change the measures being displayed in order to explore the data a little more.
Over on the forum, Hadbar asked a question about Error Bars. He asked the question back in the days of version 5, when it wasn’t straightforward to make a pleasant error bar. However, now we have the Joy of Six, we can use the new dual axis/multiple mark features to create some visually appealing error bars:
Tableau won’t calculate the error values for you, so you need those in your dataset. With this example, you need two measures:
Error – the magnitude of the error
Error lower – the lower limit of the error bar
Here’s how we build the viz. First make a regular bar chart with the relevant Dimension and Measure, as below:
To create the error bar, we build a Gantt chart on the second axis. It’s lower limit is the value of the Error lower measure, and it’s size (height) is the size of the error. Step one is to put the MIN(Error Lower) pill on the Rows shelf, and set it to use Dual Axis (click the picture to see details):
We’ve now got a dual axis graph, but there’s some way to go yet. The Error Bars need to use a different mark type, in this case a Gantt Bar. Right-click on the axis, and choose Mark Type…Gantt Bar:
Set the Size of the Gantt Bar to the size of the error. To do this, make sure the Marks shelf is showing the correct Mark. In this case, it’s MIN(Error Lower). This is a new feature in v6. In case you’ve not seen it, you can page through all the Marks:
Once you have found the correct mark, put the Error measure onto the Size shelf – that creates the Gantt bar with the height of the error. You’ll probably now notice that you have error bars, but they’re wide, and not in the right position relative to the bar. This fat bar problem is easily fixed – just slide the Size slider on the Mark shelf to be the smallest possible. That creates a nice thin line.
How to get the error bars to align correctly? Simple – right-click on the axis and choose Synchronise Axis. While you’re there, you don’t need to show the right-hand axis at all. You can’t properly hide axes in Tableau, but you can format them so they don’t appear. Right-click on the axis and choose Edit axis. Delete the title on the General tab, and in the Tick Marks tab, set the Minor and Major Tick Marks to None. Click OK and your axis has “disappeared”.
Lo and behold – you have some error bars. Play around with widths/colours and other settings to make it appear just how you want it. Coming next in the Joy Of Six series…. using parameters to create dynamic groups.
Today is the Joy of Six day. Tableau v6 is incredible, and I’ve been lucky to have had my hands on the beta versions for a while. The Tableau site itself is a great resource for learning about the amazing new features and how to use them. I wanted to do a series of posts about how these new features are already being practically applied to solve our own real world problems.
A common problem we see is that we build a view for a user, only to have them say, “Hey, that’s great, but instead of Profit, can you show Sales? Oh, and also, I’d like to see it broken down by Container, not State”. In the old days (pre v6) you had to build a view for each request. Not now. Oh no. Not now. Now you can build in masses more flexibility into your views.
The dashboard below shows an example using Tableau’s sample data:
How do we do this trick? First let’s look at the pills that build this view.
Instead of using the actual dimensions or measures, each pill is either a parameter, eg “Choose columns”, or a calculated field based on a parameter, eg “Chosen column dim”.
There are four parameters in this view (for more on Parameters, check out this video on Tableau’s own site):
Each of these is a String List, looking something like this:
Each item in the List of values box should be a Dimension (in the above image) or a Measure (not shown) you want to the user to be able to choose. You need a parameter for each user-editable area of the worksheet. In my example, that’s a parameter for Row, Colum, Bar length, and Colour.
Once you have your parameters, show them all on the worksheet (right-click on the Parameter name and choose Show parameter control).
Our next step is to connect some calculated fields to each parameter. The “Bar” calculated field looks like this:
The IF statement returns a different Measure, depending on the value of the Parameter. There are four calculated fields – one for each parameter. I created the following for the viz above:
Chosen row dim
Chosen column dim
Now you can build your view – drop the calculated fields onto the relevant shelf, and you should now have a dynamic view where the user gets to choose what they want to see.
Those of you who follow me on twitter (@acotgreave) will probably know that most Fridays I get involved in the rathe excellent FridayMix. This week it reaches its first birthday. I downloaded the full list of all 3500+ tracks that have appeared on a FridayMix and produced this viz of the most popular artists.
London 2012 published the Olympic ticket prices today. There’s lots of good value seats to be had. I took the data from the London 2012 site and built this viz that you can use to find out how much your favourite sport will cost you:
Note: this viz does not include the Opening or Closing ceremonies. Top price seats for those will set you back a max of £2,012 and £1,500 respectively! Ouch