Categorical Graphs
Suppose that you have a sample of individuals in the United States, with information on employment, earnings, and various demographic variables. Among other things, you may wish to:
• Display a bar plot comparing the mean incomes of individuals living in each state.
• Produce a scatterplot of wages and hours worked, where the subset of males is drawn using one plotting symbol, and the subset of females uses a different symbol.
• Show wage–education profiles for both male and female workers.
• Draw histograms and boxplots of wages for union and non-union workers in different industries.
These graphs are all examples of categorical graphs. Categorical graphs are observation or analytical graphs formed using subsets of the data, where the subsets are defined using the values of one or more categorical conditioning variables (which we refer to as factors). In the examples above, state of residence, gender, years of education, and union status are factors that are used to form subsets of the data, which we then use to construct the graph.
Constructing these graphs by hand can be a difficult and time consuming-process. Fortunately, EViews provides powerful tools for constructing categorical graphs directly from your data. With these tools, you may quickly and easily define your categorization, specify the graph you wish to construct, and describe the basic graph layout; additional options provide detailed control over layout and labeling of the graph, if necessary.
The remainder of this chapter describes the construction of categorical graphs of data from a series or group object using the menu item.