Degrees of Freedom
The top left corner of the best fit dialog contains the fit controls.
The degrees of freedom checkboxes in this section of the best fit dialog allow you to specify the transformation that may be permitted by restricting degrees of freedom relative to the working frame. You can lock any combination of X/Y/Z translation, X/Y/Z rotation, and scale. Any degree of freedom that is checked is unlocked—unchecking a degree of freedom locks it. Keep in mind that these degree of freedom restrictions are applied with respect to the working coordinate frame, therefore rotations are applied about the working frame origin.
As an example, suppose you have a bolt pattern measurement on a flange and you’d like to fit this measured pattern to a mating, nominal pattern. In this case, you would likely align the face of the measured points to the nominal flange face using perhaps a relationship fit, then you might wish to use the nominal bolt pattern to spin the measured flange about its axis until the bolt holes are aligned.
By locking all degrees of freedom except for rotation about the Z axis—and by placing the working frame at the center of the flange— the fit would simply clock the measured pattern to the nominals.
Notice that you can also set the instrument to a specified scale value for the fit, which allows you to apply temperature compensation to the measurements.