Hi, I’m Timble and I just completed my first week at the Data School (part of DS19). I was unsure as to what to expect in terms of what being part of the Data School would be, and how the next 16-weeks will entail.

Within the first week we got an introduction to data in the context of, data vocabulary i.e. differentiating between discrete and continuous data, ordinal and nominal data, and understanding the 5W’s of data. The majority of the week was an intro to Tableau. This was probably the most intriguing part of the week due to already having experience with it during the application process. However, it was different as we were given context as to how the systems work together. For example, I was already acquainted with parameters and action filters during the final interview data set. The issue was that I was just following a process by following YouTube and not understanding the underlying process in terms of how a parameter connects to action filters.

Some of the takeaways lessons learned was making a donut chart, creating a top-down filter, and a moving average filter. So, for this week, lets call it ‘Study Saturday’, lets make a donut chart.

Timble’s Top Tip – Making a Donut Chart in Tableau

For this example, the ‘Sample-Superstore’ dataset is being used as this is a default dataset that is built into Tableau desktop. To make the chart:

    1. Drag the ‘Segment’ measure from the ‘Data’ pane onto the ‘Color’ in the ‘Marks’ pane, and drag the ‘Profit’ measure onto the ‘Detail’ in the ‘Marks’ pane (see Figure 1).
    2. From the drop-down list in the ‘Marks’ pane, select ‘Pie’ (see Figure 1).

    Figure 1 – Dragging ‘Segment’, ‘Profit’ on to their respective marks, and changing the chart type to ‘Pie’.

        1. For the ad-hoc calculation, type “avg(0)” (you will be prompted with an auto-fill option) either in the ‘Rows’ or the ‘Columns’ section (see Figure 2).

          Figure 2 – Average calculation.

        2. Hold ‘Ctrl’ (or ‘Command’ if on Mac), and drag the existing calculation (green bubble) next to the existing calculation, resulting in two identical green bubbles next to each other and two pie charts next to each other (see Figure 3).

          Figure 3 – Calculation and chart duplication.

        3. From the ‘Marks’ pane remove the ‘Segment’ mark (see Figure 4).

          Figure 4 – Removing ‘Segment’.

        4. Change ‘Color’ to white (see Figure 5).

          Figure 5 – Color change.

        5. In the columns section click on the down arrow then select ‘Dual Axis’ (you may need to adjust the sizes of the two pie charts to make one bigger than the other, and can be done using the ‘Size’ mark) (see Figure 6).

          Figure 6 – Dual axis select.

        6. Drag the ‘Profit’ on to the ‘Label’ mark and adjust the text size and colour (see Figure 7).

          Figure 7 – Changing to text (left), and adjusting the font, size and color (right)


        7. Drag the ‘Segment’ on to the ‘Label’ mark (hold control and drag the existing ‘Segment’ bubble onto the ‘Label’), drag the ‘Profit’ onto the ‘Label’ mark and the ‘Angle’ mark as well, then adjust the text size and colour (see Figure 8).

          Figure 8 – Labelling the ‘Segment’ with the ‘Profit’ made by each segment.


        8. The end result should be something like this.

Creating the donut chart is quite interesting, and fun exercise and shows information in a very visual way. The final day was presentation day, and we had to pick a visualization from our interview process and give it a makeover. I chose to do my teams interview dashboard. It was quite simple, static, and I knew there was a lot of room for improvement. After the presentation, I felt relieved and with my improved dashboard I got good feedback which I will be taking on board

Next week I will show you how to do a top-down filter. We will be starting Alteryx next week, and I will show you an Alteryx tutorial, if I can, as well.

Here’s to another 15-weeks.

The Data School
Author: The Data School