Constructing a Best Fit or Best Fit Recompensate Cone

You can construct a best fit cone using six or more features. The first three inputs must be on an approximately planar cross section of the cone that is normal to its centerline. The remainder of the points should lie either above or below the plane defined by the first three points, but not on both sides of the plane. This method of measuring yields the best results. The best fit construction method takes the actual measured points, rather than the ball's center (as in the case of best fit recompensate). In both cases, PC-DMIS computes a least squares cone, one for which PC-DMIS minimizes the average squared distance from the data points to the cone.

To Construct a Best Fit or Best Fit Recompensate Cone:

  1. Open the Construct Cone dialog box (Insert | Feature | Constructed | Cone).

  2. From the Method list, select either the Best Fit or BF Recomp option.

  3. From the Feature list, select at least six features.

For Best Fit (BF) or Best Fit Recompensate (BFRE) constructions, while you can use any feature type for your input features, BF and BFRE fit types are typically used with point features or point sets (a scan of points, a feature set with points, or an expression that resolves to an array of points).

If you choose Best Fit Recompensate at least one feature must be a point.

  1. Select the In or Out option. For details, see the "In / Out Cone" topic in this documentation.

  2. If you want to change the feature theoretical values, select the Feature theoreticals check box and type in the values. For details, see the "Specifying Feature Theoreticals" topic in the PC-DMIS Core documentation.

  3. Click the Create button.

For a Best Fit constructed cone feature, the Edit window command line would read:

CONSTR/CONE,BF,feat_1,feat_2,feat_3,feat_4,feat_5,feat_6

PC-DMIS uses the actual measured points for construction.

For a Best Fit Recompensate constructed cone feature, the Edit window command line would read:

CONSTR/CONE,BFRE,feat_1,feat_2,feat_3,feat_4,feat_5,feat_6

PC-DMIS uses the center of the probe for measurement.


A - Best Fit Constructed Cone from Nine Points

Constructing a Cone from Six or More Points