### Best Fit Options for Line Profile Dimensions

Note: This area only appears on the dialog box if you select the Form Only option from the Control Options area.

The Best Fit Options area lets you create an internal Best Fit alignment on the dimensioned feature using one of these available methods:

- No Fit - No alignment is created.

- Least Squares - This fit finds a position where the deviations are minimized. In this way, the Form Only option can ignore the location of the feature while checking that the curve is close to the nominal shape.

- Vector - This fit snaps errors in the input features onto the theoretical vectors before minimizing the average squared error.

- Min / Max - This fit minimizes the maximum error in all of the input features.

- Optimized - This fit allows the measured data to shift and rotate within the tolerance domain until the data fits. You can also specify the lower tolerance value which typically is not allowed to change from 0.0 for the other fitting types.

Work Plane

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. Selecting a workplane that differs from the two-dimensional projection of the curve results in an incorrect calculation.

See the "Creating a Best Fit Alignment" topic in the "Creating and Using Alignments" section.