Third day at the Data School for us DS16ers, and the moment we were all waiting for: the start of our training on Tableau (hurrah!). We went through the fundamentals of how to use Tableau and the different types of (basic) charts that could be built. Some of that learning I already knew and others were epiphany type moments where I realised that, had I known this when I was building my application, my life would have been so much easier!

Here’s my top 3 pick of what we’ve learnt today:

  1. Discreet vs continuous:

Discreet fields will be coloured in blue whilst continuous fields will be green. Ever wondered why there are two of the sub-categories to choose from when you want to have more details in a date field? The first one will make your chosen date level of detail discreet and will break down your chart by quarter for example, whilst the second one will make it continuous and show an unbroken line (if you are doing a line chart).

2. Heatmaps

I had never done one before, and even though they look really cool they also look quite complicated to make. Whilst in fact, they are super easy!

Say you want to show energy consumption by day and month over the course of 1 year. Just drag the day field (or date, which you will need to bring to a level of detail as a weekday discreet field) in the column section, then the month field (or adjust the date field as previously) in the row and finally the energy consumption in the colour marks and hey presto, you’ve got a heatmap!    

3. How to avoid having to change your aggregate calculation all the time

By default, Tableau will aggregate any measure that you drag onto your worksheet as a SUM, which might not always be what you want to see. If you want to avoid having to change it to the most appropriate aggregation every time you start a new chart, simply right click on the measure => default properties => aggregation and select whichever one you want. Boom!