Background

Recently, Melbourne cohort DSAU15 at the The Data School Down Under participated in a global client project. For this project, each Data Schooler was assigned with formatting and improving Tableau dashboards using their visualisation guidelines.

While looking through the worksheets in my assigned dashboards I came across a method that was used to create separate legends for each column. To improve the dashboard I set out to make it simpler version which would achieve the same goal.

 Outline

In this blog post I will be showcasing two methods as to how to have separate colour ranges for separate columns in your heat map. Method 1 will go over a more complicated method and Method 2 will be a simpler method with better performance. 

Method 1

The first method is slightly more complicated and a little bit more work. Here’s what the worksheet looks like:

Each column uses a different colour range

 

To begin, create a created field with Min(1.0) and then drag it onto the columns. Drag as many of that calculated field as you would like columns.

What this does is create an axis in which we change the chart type into bar.

We then drag the measure we are looking to colour to the text and colour box for each mark tab. It will look like this:

3 columns, 3 marks

What about headers for the columns? One solution the client used was to create more columns and dual axis them with the pre-existing columns.

After dual axis-ing the charts we turn we edit the top axis of each column and rename it to the desired header. You will also need to hide the second chart by changing it into a gantt, reducing its size and opacity.

Dual axis + changing the top axis title + changing size and opacity of second charts for each column

 

Another thing to remember to do is to turn off the axis ticks….

Hide those axis ticks

…and also hide the bottom axis by editing the axis and leaving the title blank

Keep the Axis Title blank

 

And this is one method of building separate coloured columns for a heat map!

Method 1 Pros

One of the positive things about using this method is that each mark (and therefore column) can be customised even further. For example you can have each column display a different tooltip or text.

Method 1 Cons

Unfortunately, this method is tedious and it can take some time to build. Furthermore with all that is going on, the worksheet’s performance will be affected.

Method 2

Here I will present a simpler method as to how to create separate coloured columns in a heat map.

To create the table, while there is a dimension in rows simply click and drag the measure you want to see the values of onto the canvas until “Show me” appears

Drag your measure (green pill) until this appears

Repeat the process for other measure values you would like to view as well

It should begin to look like this

You may notice that there’s only a single Marks card that uses the ‘Measure Values’ pill.

While holding down the ‘CTRL’ button, click and drag that pill to the Colour box. What should happen is that the whole table will be coloured by a range.

it will colour the whole table

Now that we’ve coloured the table, there is one more step.

Right click on the ‘Measure Values’ pill that is attached to colour and select the ‘Separate Legends’

This option will make every measure have its own colour legend

After some formatting and changing colours, the end table can look like this.

Method 2 Pros

One of the great things about this method is its simplicity. It takes less steps to create and it is also better for performance. With some formatting you can even add space within the table (just change the colour of the lines)

Another thing I like about this version is that the columns can added or removed at ease.

Method 2 Cons

This will be the inverse to Method 1’s benefits – That is, we are unable to manually configure each column’s tooltips.

Conclusion

There it is. Two methods to colour your columns.

I hope you found these tips useful.

If you would like to contact me, please feel free to connect with and message me over at LinkedIn.

Thank you for reading and have a great day!

The Data School
Author: The Data School