This example is intended to illustrate a use case of tags.

In a health investigation, Height (m), Weight (kg), and BMI (Body Mass Index) are registered for a number of people in the data table below.

Assume it is of interest to distinguish individuals with a BMI value higher than 30, and individuals with a BMI value lower than 30, for example, in a scatter plot, where the weights are plotted against the heights. You can do that by attaching different tags to the data rows.

First, create a tag collection. Select View > Tags on the menu bar to open the Tags panel, and click New tag collection, .

In the New tag collection dialog, give the tag collection a Name, and create the tags via New.

The Tags panel now shows the tag collection and its tags.

No tags have yet been attached to any rows, as indicated by the zeros in the parentheses. To attach tags, locate the rows you want to attach a tag to, for example, by sorting the BMI column in the table, and mark the rows with a BMI value above 30. Then select the BMI>30 tag in the Tags panel, and click Attach tag to marked rows, . In the same way, attach the BMI<30 tag to the remaining rows.

The number of rows that have been attached with a certain tag is shown in the parentheses.

Note: The created tag collection results in a new data column, and a new filter, as shown below.

Once tags have been attached, you simply double-click a tag in the Tags panel, and its associated rows become marked in the visualizations. For example, when you double-click the BMI>30 tag, the following individuals have a BMI higher than 30 in the scatter plot.