This area only appears in the dialog box if you select the Form Only option in the Control options area.
The Best Fit Options area in the Line Profile dialog box (Insert | Dimension | Profile | Line) lets you create an internal Best Fit alignment on the dimensioned feature using one of these available fitting methods:
NO FIT - This does not create an alignment.
For descriptions of LEAST_SQR, VECTOR_LST_SQR, MIN_MAX, and VECTOR_MIN_MAX, see "The Best Fit Alignment Methods" in the "Creating and Using Alignments" chapter.
OPTIMIZED - This fit uses a genetic algorithm to determine if the data passes or fails the Line Profile dimension. You can also specify the lower tolerance value. (Typically, with the other fitting methods, you can't change the tolerance from 0.0.)
Workplane
When you use the line profile dimension, PC-DMIS creates an internal two-dimensional alignment that rotates and translates in all directions within the selected workplane to minimize the deviations of the individual hits. If you select a workplane that differs from the two-dimensional projection of the curve, an incorrect calculation results.