Basic Analysis and Graphing - SAS

Chapter 11 Creating Summary Charts 319
Example of the Chart Platform
X Y Type of Chart
one or two none Plots the counts for each level of the X variable. For two X variables, the
counts for each level of both X variables are included (or overlaid) in a
single chart. See “Plot Counts of Variable Levels” on page 328, for an
example.
one or two one or more Plots the selected statistics for each level of the X variable. For two X
variables, the selected statistics for each level of the X variables are included
(or overlaid) in a single chart. See “Plot Multiple Statistics” on page 327,
and “Plot Multiple Statistics with Two X Variables” on page 330, for
examples.
Use Grouping Variables
If you specify one grouping variable, the result is a separate chart for each level of the grouping variable. All
charts are under the same outline title. If you used the same variable as a By variable instead, the same
separate charts are produced, but each chart is under its own outline title.
If you specify two or more grouping variables, the result is a matrix of charts. Each chart shows a
combination of one level from each of the grouping variables.
If there are multiple statistics, the Overlay option is checked by default, and the Y variables (statistics) are
plotted on the same chart for each level of the grouping variable. However, the levels of the grouping
variable cannot be overlaid into the same plot frame. For example, if the levels of your grouping variable are
Male and Female, the Overlay option cannot be used to combine the two Male and Female graphs into one
graph. To see that type of result, use Categories, X, Levels instead of Grouping variables.
Related Information
• “Example Using Two Grouping Variables” on page 324
• “Example Using Two Grouping Variables and Two Category Variables” on page 325
Adding Error Bars
Error bars are available when the Mean statistic is selected for at least one Y variable, and at least one X
variable is assigned. Error Bars are not available for pie charts. Selecting Add Error Bars to Mean causes
additional options to appear in the Chart launch window.
After the option is checked, select a type of error bar from the menu that appears. Some of the types of error
bar have an additional numeric field. The following table describes the different types of error bars that are
available.
Range
Standard Error
Creates error bars based on the range of the data.
Creates error bars based on the standard error of the mean. You can
specify the number of standard errors.