Best Fit Alignment

Command Description

The Best Fit Alignment command allows you to fit straight lines or tangential curves horizontally through multiple selected points or free screen locations. It dynamically displays error residuals for each attached segment, allowing you to include or exclude specific points and apply custom weights to adjust their influence on the final alignment.

Command Photo Demo Video

• Input:
  • Choose the Segment type—Straight or Curve—that you want to fit through the selected points.
• Use the selection picker to choose points or free screen locations. If you select the wrong point, click Undo to remove the previous selection.
• Segments:
  • After selecting all points for a segment, click Add to lock in the segment and move to the next one. If you do not need the last segment you added, click Remove to delete it.
  • Each segment is listed in the table with the following details:
    • Start and End – The point numbers shown on screen.
    • Fit – The segment type used, Straight or Curve. This can be changed in the table.
    • Side – Controls the direction of the curve, Left or Right. It will be set to Auto to begin with but can be overridden.
    • Sweep – This is the arc length and will be set to Auto to begin with. It can be overridden to use a Short arc (< 180°) or Long arc (> 180°) between the points.
• Output:
  • Select a Layer from the list, or create a new one, for the final linestring.
  • Select a Colour for the new linestring.
  • Enter an Elevation for the linestring. The entire line will be set to this elevation, and one must be entered.
• Points:
  • Check the Create points box to create a point at each picked location.
  • Select a Layer from the list, or create a new one, for the points to be drawn on.
  • Enter an optional Feature code to apply to the points.
• Residual display:
  • Each point is listed in the table with the following details:
    • Point – The point number.
    • Offset – The distance of the point either side of the best-fit line.
    • Chainage – The distance along the best-fit line.
    • Weight – A value from 0 to 1 that controls the point’s influence on the line geometry.
    • Include – If selected, the point is included in the best-fit calculation.
    • Geometry – Shows which segment the point is part of and whether it is straight or curved, and the radius.
• Click Create Report to export the residual display table to an Excel sheet.
• Click Clear to remove all stored points and segments and start again.
• Click Apply to create the final best-fit linestring and restart the command. If you need an Excel report of the residuals, create it before clicking Apply.
• Click Close to end the command.