Profiler - Specifications for Factor Grid

Click the Factor grid button on the Profiler dialog box - Quick tab to display the Specifications for Factor Grid dialog box. Use this dialog box to specify the minimum value, the maximum value, and the number of intervals in the grid for the factor. These specifications determine the grid points for the factor, by setting the lowest grid point to the minimum value, the next lowest grid point to the minimum value plus the difference of the minimum value from the maximum value divided by the number of intervals, and so on up to the highest grid point.

<<Prev./Next>>/Factor.

Two methods are available for changing the factor for which you want to specify grid points without returning to the Profiler dialog box. You can click the Next>> and <<Prev. buttons to cycle through the factors in the analysis in the order, or reverse order, respectively, in which they were selected to be included in the analysis. You can also select a factor for which you want to specify grid points by selecting the factor from the Factor box under the Next>> and <<Prev. buttons.

Minimum/Maximum

Grid points serve two functions in the Profiler. They determine the plot points for the factors on the prediction profile compound graph and the surface and contour plots. They also determine the levels of the factors for which predicted values for the dependent variables are computed when the Set factors At optimum value option is selected on the Profiler dialog box - Quick tab and the Optimum desirability at exact grid points method is specified on the Profiler dialog box - Options tab. Large numbers of grid points should be avoided when these options are used to avoid unexpectedly long grid searches (see Profiler dialog box - Options tab for details). Changing the grid points for the factors only affects the graphical output if the Set factors At optimum value option is not selected, or the Optimum desirability at exact grid points method is not specified.

Note: for mixture designs, the specified factor minimum and maximum values must be within the observed range of values for the respective factors. This constraint does not apply for other types of designs.

No. of steps.

Enter a value in the No. of steps box to specify the number of intervals to apply to the specified variable. For more information, see the Optimum desirability at exact grid points option on the Profiler dialog box - Options tab.

Apply to all

Click the Apply to all button to apply the same specification of number of intervals to all the predictor variables in the analysis.

OK

Click the OK button to accept the entries made in the Specifications for Factor Grid dialog box and return to the Profiler dialog box.