How to build and interpret an index chart using Tableau

The index chart is a chart type that often comes in extremely useful for analysing the change in time series data.

You’ve probably seen these charts frequently used in finance – such as tracking a financial index like the S&P500. Here’s an example pulled from Statista looking at US Stock Indices since the start of 2022.

Notice how all series start at the same point, and the chart plots the relative change in each series over time. We can immediately see that NASDAQ has performed relatively poorer than the Dow Jones and S&P 500 during this period.

As you might … Read the rest

Using a parameter to filter for specific records in a Tableau dashboard or worksheet

Filters are great and all, but I genuinely love Tableau parameters.

One technique that I frequently use for certain dashboard designs is using a parameter as the
primary method of interaction. That is, I use parameters to take input from users, which primarily drives the data viewed on screen. The parameter filters worksheets and shows related information about that input, acting much like a database record selection action or a filter in an Excel spreadsheet column.

For example, say you have a dashboard filled with customer activity for a large retailer. The dashboard might show overall sales per customer, … Read the rest

The importance of exploratory data analysis: Exploring the first B2VB challenge

I kicked off the year participating in a brand-new data visualisation curated by
Eric Balash. It’s called ‘Back to Viz Basics’, also known by its hashtag #B2VB. It’s a fortnightly challenge where the data visualisation community – both new and old – come together to practice some core charting skills. You can read about the initiative here.

The first ‘official’ challenge was on the theme of the scatter plot, a chart type that’s a core communication tool of the data professional. Eric challenged us to analyse some
American college basketball data, specifically on coaching, to … Read the rest

A Cost of Insecurity – Comparing Spending on Military Capability v the Human Development Index

One great thing about the company I work for is that they continually encourage us to develop our skills via monthly data visualisation challenges. The latest challenge was themed on ‘scatter plots’ and it was definitely one I wished to be a part of – I love scatter plots!

Harking back to my postgraduate studies in international relations, I had sourced some data from the Stockholm International Peace Research Institute around the percentage of GDP various countries use to support their military capability. I was very keen to do some analysis using this data but momentarily stuck with what to … Read the rest

Fun with sets: Highlighting/filtering data using a shared attribute of a selected value in Tableau

Have you ever wanted to be able to filter or highlight records in a Tableau visualisation that share a common attribute? For example, say you had a visualisation and a filter that listed animals. You select ‘kangaroo’, and the visualisation would filter for ‘kangaroo’ and all other marsupials – animals that share the same infraclass as the chosen ‘kangaroo’.

Typically, when filtering in Tableau, you filter on a single dimension or measure and the filter action is limited to whatever you selected. Using the example above, if I chose ‘kangaroo’, the visualisation would filter for kangaroos but no other, unless … Read the rest

The Land is a Map: On being awarded Viz of the Day

Last week I was fortunate enough to be awarded my first ever ‘Viz of the Day’ (or VOTD). The more expansive (and I think better version) of the visualisation can be found on my Tableau Public profile.

If you don’t have a clue about what I’m talking about, Tableau – the purveyor of fine data visualisation software – regularly select a visualisation from the community to showcase most weekdays. Typically, VOTD often showcases an interesting new technique or visualisations that provide information on current news or relevant historical events or generates fascinating new insights.

In the case of … Read the rest