Using gret l for Principles of Econometrics, 4th Edition
Graph the Data
To generate a graph of the food expenditure data that resembles the one in Figure 2.6 of POE,
you can use the 1= button on the gretl toolbar (third button from the right). Clicking this button brings up a dialog to plot the two variables against one another. Figure 2.4 shows this dialog where x is placed on the x-axis and y on the y-axis. The result appears in Figure 2.5. Notice that the labels applied above now appear on the axes of the graph.
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Figure 2.5 plots food expenditures on the y axis and Weekly Income on the x. Gretl, by default, also plots the fitted regression line. The benefits of assigning labels to the variables becomes more obvious. Both X - and Y-axes are informatively labeled and the graph title is changed as well. More on this later.
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Fife |
lools Data |
View Add Sample Variable |
Model HelD |
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food. gdt |
w Ordinary Least Squares...) |
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ID# * |
Variable name < Descriptive label |
Instrumental variables |
► |
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0 |
const |
auto-generated constant |
Other linear models |
► |
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1 |
food_exp |
household food expenditure |
Nonlinear models |
► |
■ |
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l |
income |
weekly household income | |
Time series |
► |
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Figure 2.7: The Specify Model dialog box opens when you select Model>Ordinary least squares |
