Tableau Public: Data processing and visualization
This article will demonstrate the use of Tableau Public Edition visualization platform. For the practical purpose of making this demonstration a research project two data sets were selected: the Global Peace Index and the World Happiness Report.
Prerequisites: Tableau Public, Excel, data files
Tableau Public
Tableau Public is a free desktop application used to create interactive graphs, animations and maps within dashboards, and live dashboards creation in minutes. In Tableau world, such a visualization is called a ‘viz’. Viz may be saved to your Tableau Public profile and shared anywhere on the web. Each profile is allowed 10 GB of online space. Multiple visualizations may be created. You may review dashboards by other authors, follow them, learn from them, and build your own online presence. There are 750.000 dashboards presented in Tableau Public space.
Installing Tableau Public
Download a desktop application from https://public.tableau.com/ and install it to start.
Connecting to Data
Once you open your workbook, the first step is to connect to data. There are many types of connections available.
For this demonstration, two public data sets were downloaded.
The goal is to explore the ranking of countries by comparing their standing using various parameters.
“The World Happiness Report is an annual publication of the United Nations Sustainable Development Solutions Network… The rankings of national happiness are based on a Cantril ladder survey. Nationally representative samples of respondents are asked to think of a ladder, with the best possible life for them being a 10, and the worst possible life being a 0. They are then asked to rate their own current lives on that 0 to 10 scale. The report correlates the results with various life factors.” — (source: Wikipedia)
The data set used for this demonstration may be download from https://worldhappiness.report/ed/2020/
During the work on the visualization of World Happiness Data and experimentation with Tableau
Tableau Public offers many advanced features: joins, pivoting, offers several advanced features. Pivoting and Joining data.
Join is an operation that connects two tables by joining their columns and expanding columns of resulting table.
While exploring data in the World Happiness Report it was decided to test the joining of another index table. It was decided that it will be:
“Global Peace Index (GPI) measures the relative position of nations’ and regions’ peacefulness. The GPI ranks 172 independent states and territories (99.7 percent of the world’s population) according to their levels of peacefulness. In the past decade, the GPI has presented trends of increased global violence and less peacefulness. ” — (source: Wikipedia)
Global Peace Index (GPI) data are presented in the table on the same Wikipedia page. The content of the table was copied and pasted into Excel. Data preparation was done in Excel (trimming strings, removing ‘=’ indicating the same country rank, header renaming). In addition, the main sheet has been split into Rank and Score sheets, of which only the Rank sheet is used.
Tip: Use ‘Paste Values’ to avoid pasting images of flags into an Excel spreadsheet.
All data were saved as Excel files and stored in a folder (Figure 2.)
Tip: Rename sheet in each of the files. The new names accurately representing content more will be visible in Tableau Desktop once the connection with the source is made.
Connecting to the data sources
Open the Tableau Public and proceed with Connect. The first file to connect to is the Global Peace Index.
Once connected to the Global Peace Index and from it, the sheet Rank, the data will appear in Tableau application. Columns with year caption have to be pivoted. Just select all years column and apply the Pivot option.
Once a second file is connected, Tableau will recognize that they may be joined. This is an opportunity to adjust the relations and do the join on Country and Year.
The rest is just experimenting and learning how Tableau works.
The table is here:
Publishing the visualization
From within the desktop studio application, a visualization may be saved to public space. It may stay hidden if you still are working on ot.
