You can use the Calculation list in the Advanced measurement options area to specify how you would like the feature calculated from the measured hits. This list is available for the Circle, Cylinder, and Plane Auto features.
PC-DMIS dynamically filters the available options. The list of options depend on the type of feature that you select and whether the feature is an Inner (hole) or Outer (stud) feature type.
The available options for Circle and Cylinder features are:
LEAST_SQR, MIN_SEP, MAX_INSC, MIN_CIRCSC, and FIXED_RAD
The available options for the Plane feature are:
LEAST_SQR and MIN_SEP
For legacy Circularity and Cylindricity dimensions, as well as a Location dimension's RN Line, the feature solution is used to compute the dimension. By default, this is Least Squares. However, you can choose to solve the feature using Minimum Separation, Maximum Inscribed, Minimum Circumscribed, or Fixed Radius regression algorithms.
FCF Circularity and Cylindricity, on the other hand, are computed using the Chebyshev algorithm (Min/Max) as required by the Y14.5 standard. Because of the change in calculation, Circularity and Cylindricity FCF dimensions are generally computed to a slightly smaller value than their legacy counterparts.
These calculation types are already discussed in detail in the "Best Fit Type" topic in the "Constructing New Features from Existing Features" chapter.