While working on a project in datacamp this week, I was using a log scale on a bar chart because it was the most effective way to communicate. (NOTE: See this article from Naomi Robbins for more info about appropriate use of log scales.) I ran into an interesting phenomenon in Tableau, which I believe is a bug, but I kind of like.
Let’s start with a simple bar chart with three different label alignment options.
Some quick notes:
- The length of the bars in all of these examples is represented by the field “Value”
- The label is represented by the field “% of Value”.
- These charts all use the default scale.
These charts look as I expect. Auto, left and right align are placing the labels in the expected location.
However, look what happens when I change the scale to logarithmic.
- Auto alignment has suddenly become left align.
- Left alignment is now right aligned, but inside the end of the bar.
- Right alignment is now left aligned.
When I filter down to just the top 10, the behavior changes again.
- I definitely think this is a bug, and I’ve reported this because Tableau is providing an inconsistent and unexpected user experience.
- I really like the look of the bar label inside the end of the bar. I would like more flexibility with label alignment to be able to get this look intentionally.
- If you want to hear about lots of the cool stuff we’re doing with Tableau at Facebook, come here our talk at TCC13 at 11am on Wednesday – “Interworks: Data Discovery at Facebook: Why Culture & Flexibility Matter for Modern Analytics”.
If you want to play with it yourself, you can download the workbook here.