Stat > Regression > Nonlinear Regression > Catalog
Use to select a predefined expectation function. You can select a function that is supplied by Minitab or a custom function that you have previously entered. Minitab automatically adds a custom function to the catalog when you first use it to perform a nonlinear regression analysis. After you choose a function and click OK, Minitab prompts you to choose predictors for each placeholder.
Show functions: If you like, select a category to filter the list of functions.
Function: Choose the expectation function.