Box Plot Task

Example: Box Plots Comparing MPG (City) for Cars

About the Box Plot Task

The Box Plot task creates a single box plot, which represents numeric values measured as intervals. If you choose to categorize the values of the analysis variable, then multiple box plots are created.

Example: Box Plots Comparing MPG (City) for Cars

This example creates three box plots that compares how many miles per gallon (city) cars consume depending on their area of origin (Asia, Europe, and United States).

To create this example:

In the Tasks section, expand the Graph folder and double-click Box Plot. The user interface for the Box Plot task opens.
On the Data tab, select the SASHELP.CARS data set.

Assign columns to these roles:

Role	Column Name
Analysis variable	MPG_City
Category variable	Origin

To run the task, click .

Here is the resulting box plot:

Assigning Data to Roles

You can subset the data in the input data set by applying an SQL WHERE clause. In the Where string box, enter your valid SQL syntax. You must enclose character strings in single quotation marks. To view this WHERE clause with the resulting graph, select the Include as footnote check box.

To run the Box Plot task, you must assign a column to the Analysis variable role. You can create either a vertical box plot or a horizontal box plot.

Role	Description
Analysis variable	specifies the analysis variable for the plot.
Category variable	creates a box plot for each distinct value of the category variable.
Group variable	specifies a variable that is used to group the data.
BY variable	creates a separate graph for each BY group.

Setting Options

Option Name	Description
Title and Footnote
You can specify a custom title and footnote for the output. You can also specify the font size for this text.
Box Detail
Box width	specifies the width of each box. Specify a value between 0.0 (0% of the available width) and 1.0 (100% of the available width).
Fill	specifies whether the boxes are filled with color. The default color is white.
Data skin	specifies a special effect to be used on the plot. The data skin affects all filled boxes. The effect that a data skin has on a filled area depends on the skin type, the graph style, and the color of the skinned element. Most of the skins work best with lighter colors over a medium to large filled area.
Transparency	specifies the degree of transparency for the plot. The default value is 0. However, valid values range from 0 (completely opaque) to 1 (completely transparent).
Set cap shape	specifies whether to display the cap lines for the whiskers. If you select this option, you can select the shape of the whisker cap lines. Here are the valid values: Bracket displays a straight line with brackets. Line displays a straight line. Serif displays a short straight line.
Notches	specifies that the boxes be notched. The endpoints of the notches are at the following computed locations: $m e d i eh n plus minus , 1.58 , open . fraction i q r , over square root of n end fraction . close$
Group Layout
Group Order	specifies the orderi of boxes within a group. The groups can be displayed in ascending order, in descending order, or in the order in which they appear in the data.
Category Axis
Reverse	specifies that the values for the tick marks are displayed in reverse (descending) order.
Show values in data order	places the discrete values for the tick marks in the order in which they appear in the data.
Show label	enables you to display a label for the axis. Enter this label in the Custom label box.
Analysis Axis
Show grid	creates grid lines at each tick on the axis.
Show label	specifies whether to display the label for the analysis axis. By default, the axis label is the name of the variable. However, you can create a custom label.
Legend Details
Legend location	specifies whether the legend is placed outside or inside the axis area.
Graph Size
You can specify the width and height of the graph in inches, centimeters, or pixels.