Modeling and Multivariate Methods - SAS

Chapter 9 Performing Nonlinear Regression 247
Nonlinear Fitting with Fit Curve
4. Click OK.
5. On the Fit Curve red triangle menu, select one of the models. The models are described in “Fit Curve
Models and Options” on page 247.
Fit Curve Models and Options
The Fit Curve red triangle menu contains the following models and options. For details about the model
formulas, see “Model Formulas” on page 247.
Polynomials
Fits first degree to fifth degree polynomials.
Sigmoid Curves Fits Logistic and Gompertz models. These models have both upper and lower
asymptotes. The Logistic 2P, 3P, and 4P models are symmetric. The Logistic 5P and both Gompertz
models are not symmetric. The Logistic 2P is available only when the response is between 0 and 1.
Exponential Growth and Decay Fits Exponential, Biexponential, and Mechanistic Growth models. The
Exponential 2P and 3P are similar, but the 3P model has an asymptote. The Biexponential models
assume there are two separate growth or decay processes. The Mechanistic Growth and Exponential 3P
models alway increase, but the rate of growth slows so that the model has an asymptote.
Peak Models Fits Gaussian Peak and Lorentzian Peak models. These models increase up to a mode
(peak) then decrease. The Gaussian Peak model is a scaled version of the Gaussian probability density
function (pdf). The Lorentzian Peak model is a scaled version of the Cauchy pdf.
Pharmacokinetic Models Fits the One Compartment Oral Dose model, the Two Compartment IV
Bolus Dose model, and the Biexponential 4P model. Select this option to model the concentration of
the drug in the body.
Fit Michaelis Menten
Fits the Michaelis-Menten biochemical kinetics model.
Script
Contains options that are available to all platforms. See Using JMP.
Model Formulas
Table 9.1 provides the formulas for the models on the Fit Curve red triangle menu.
Table 9.1 Fit Curve Model Formulas
Model
Polynomials
Formula
k
β 0
+ β i
x i
i = 1
where k is the order of the polynomial. These models can also
be fit using the Fit Model and Fit Y by X platforms.