This section provides an example of creating the formula column for a model, and fitting the model in the Nonlinear platform. The data is in the US Population.jmp data table. The response variable is the population (in millions) of the Unites States and the predictor is the year.
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Create a new column called Model.
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Select Parameters from the list below the list of columns.
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Select New Parameter.
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Click OK.
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Select New Parameter.
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Click OK.
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Enter the model formula using the Formula Editor functions, the column year, and the parameters. Figure 12.2 shows the completed model.
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Figure 12.2 Completed Model Formula
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Click OK.
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Select Analyze > Specialized Modeling > Nonlinear.
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Click OK.
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Click Go on the Control Panel to fit the model.
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Figure 12.3 Plot and Solution Report
The final parameter estimates are shown in the Solution report, along with other fit statistics. The fitted model is shown on the plot.
In the formula editor, when you add a parameter, note the check box for Expand Into Categories, selecting column. This option is used to add several parameters (one for each level of a categorical variable for example) at once. When you select this option, a dialog appears that enables you to select a column. After selection, a new parameter appears in the Parameters list with the name D_column, where D is the name that you gave the parameter. When you use this parameter in the formula, a Match expression is inserted, containing a separate parameter for each level of the grouping variable.