In many situations, especially in the physical and biological sciences, well-known nonlinear equations describe the relationship between variables. For example, bioassay experiments are conducted by pharmacology researchers to understand how the strength of the response to a drug changes as a function of drug concentration. The Logistic family of curves often accurately describes how the response strength is related to drug concentration. Another example is exponential growth curves, which can predict the size of a population over time.
The Nonlinear platform’s Fit Curve personality provides predefined models, such as polynomial, logistic, Gompertz, exponential, peak, and pharmacokinetic models. Fit Curve also enables you to compare different groups or subjects using a variety of analytical and graphical techniques.
You might prefer to create your own nonlinear models, which include a model formula and initial parameter estimates. See Nonlinear Regression with Custom Models section for details.