Complete Example Using the Fit Curve Personality in Fit Curve to fit the model. This example shows how to save the prediction formula from Fit Curve and then set parameter limits in Nonlinear.
From the Logistic 4P red triangle menu, select Save Formulas > Save Parametric Prediction Formula.
A new column named Toxicity Predictor appears in the data table.
Select Analyze > Specialized Modeling > Nonlinear.
Assign Toxicity to the Y, Response role.
Assign Toxicity Predictor to the X, Predictor Formula role.
Assign Formulation to the Group role.
The Nonlinear Fit window appears (Nonlinear Fit Control Panel). In the Control Panel, parameter values and locking options are shown. The letters listed before each parameter correspond to variables from the Prediction Model in the Fit Curve function.
Nonlinear Fit Control Panel
Select the red triangle menu next to Nonlinear Fit and then select Parameter Bounds.
Set the lower bounds for the parameters as shown in Setting Parameter Bounds. You know from prior experience that the maximum toxicity of the drug is at least 1.1.
Setting Parameter Bounds
The final parameter estimates are shown in the Solution report, along with other fit statistics (Nonlinear Fit Plot and Parameter Estimates). The fitted model is shown on the plot.
Nonlinear Fit Plot and Parameter Estimates

Help created on 9/19/2017