Data Visualization, Tableau
A step-by-step tutorial in Tableau to split a trendline year by year
I’ve been trying to learn Tableau for a while now. For those who don’t know, Tableau is software (paid, but with a trial or even free version for students and teachers) that allows you to explore and visualize data. At first glance, it is a very complex software, because it allows you to do many things, including creating single more or less complex graphs, dashboards, and stories. You can’t find a lot of resources explaining how to do this or that in Tableau. There are tons of books, courses, people to follow on LinkedIn, etc. I’m not here to list my favorites, but if you’re interested, leave a comment at the end of this article or contact me privately on LinkedIn.
However, despite the countless resources available on the web, I was unable to find the one that was right for me, so I decided to write a separate tutorial, who knows, maybe it will make life easier for those who, like me, have undertaken this fearless journey into the world of Tableau.
The problem I had to solve was to organize a line showing the trend over time for years and display the years in an overlaid manner, just as shown in the figure below.
I found several tutorials on the web that showed how to organize the years by months or quarters, but in my case, the problem was different because I wanted to display every single day of the year. So let’s proceed step by step and see how I managed to create this figure.
My goal is to represent air temperature data over time. I took these data from the Copernicus website, which makes them publicly available and indeed represents them using a graph very similar to the one I represented.
Let’s download the dataset as CVS and import it into Tableau. But first, open the file with a text editor and delete the first seven…