Box plot

Box plots are graphical tools to visualize key statistical measures, such as median, mean and quartiles.

Note: Some of the functionality of box plots can only be authored in the installed client.

A single box plot can be used to represent all the data. It is also possible to show separate statistics for subsets of the data by selecting a column for the category axis.

The individual box plot is a visual aid to examining key statistical properties of a variable. The diagram below shows how the shape of a box plot encodes these properties. The range of the vertical scale is from the minimum to the maximum value of the selected column, or, to the highest or lowest of the displayed reference points.

Which reference points should be shown in the box plot is specified upon configuration of the visualization. A reference point can be indicated by either a marker or a line, and you can specify its color and shape. For details of each measure, see Aggregations and statistical measures.

The axis selectors control which column is mapped to which axis. See Selecting columns on an axis for more information about how they work.

The value axis should be set to the column or columns on which the statistical measures should be based. You can adjust the scales and scale labels in the visualization properties. You can also choose to use a Relative scale which sets the max and min for all box plots to 100% and 0% respectively.

A separate box is drawn for each unique value in the column or hierarchy on the category axis, and because of this, it should not contain too many unique values. To summarize the data in a single box, select (None) on the category axis. If multiple columns are used on the value axis, '(Column Names)' must be used either on the category axis or in one of the trellis options.

Settings like the box width, marker size, and transparency can be changed in the visualization properties, under Appearance. You can also add zoom sliders or horizontal gridlines from the visualization properties. If you prefer the box plot to be shown horizontally, locate the orientation section under Appearance and click Horizontal.

Tip: You can also right-click in the visualization and change the orientation of the box plot from the pop-up menu directly.

All visualizations can be configured to show data limited by one or more markings in other visualizations only (details visualizations). Box plots can also be limited by one or more filterings. Another alternative is to configure a box plot without any filtering at all. See Adding data limitations for a visualization for more information.