The radial chart on the left visualizes the 4 clusters which were obtained from x-means clustering on pre-treatment questionnaire data for 1,228 tinnitus patients.
The radial chart depicts cluster averages for each feature. Since each feature was scaled (z-score normalized) before clustering, it is thus possible to show features with originally different scales in a combined visualization. Values are in terms of standard deviations from the mean. For example, if the bar or point of a feature is +1.0, it means that the average feature value is one standard deviation above the feature average of all patients.
Using the radio buttons, you can select either "All" to juxtapose all clusters within one chart, or you can select a specific cluster to inspect cluster averages as colored bars and standard errors (grey lines).
While the radial chart provides a compact summary of one or all clusters, we often want to compare the clusters in more detail. Hence, to display the original (unnormalized) distribution of a feature you can either click on the feature's name in the radial chart or select the feature from the dropdown list. Population averages are displayed as black solid lines.
If a particular cluster is selected, you have the option to show also the post-treatment values. Pre- and post-treatment values are shown as bar right next to each other. The color of the arrows and feature labels illustrates the treatment effect.