Today’s task in Dashboard Week was to look at NOAA data surrounding both El Niño and La Niña. You can see my dashboard about this here, but in this blog I thought I’d share a very very quick tip that Laura showed me today. If you’ve seen any of my stuff on Tableau Public, you’ll be aware how much I love a dual axis chart. However, I’ve always felt just a little bit confined by them until Laura opened my eyes to the wonder of this one little trick.
Lines and Bars
As you can see in my viz I have a line graph with specific areas highlighted in blue and red. To do this I had dual axes. 1 bar chart to create the bands of colour, and then a line chart to show the progression of the Southern Oscillation Index over time. So far so standard. If we filter down to a smaller date sample, and turn up the opacity of the bars you can more easily see how Tableau defaults dual axes. The measure on the right in the rows gets placed in front of the measure on the left.
This was a problem for me as the axis I wanted to show on the left of my chart was the line graph, which was also the measure I wanted to be in front. Thankfully, as I said earlier, Laura was there to save the day. What I didn’t know until today was that if you right click an axis (when you have a dual axis chart) you can choose whether you want that measure in front or behind. Day 2 of #dashboardweek saved, bring on day 3.
Hopefully you found this blog useful and/or interesting. If you have any comments/feedback/questions then find me on twitter @olliehclarke.