The data used to construct the line is determined as follows:
First, a segment of the scan is determined using a starting point and an ending point within the scan. The starting and ending points are chosen as the point in the scan nearest [start_x, start_y, start_z] and the point nearest [end_x, end_y, end_z], respectively.
Points are then discarded from the start and end points of the scan. The number of points discarded is discard_start and discard_end from the start and end, respectively. A line is then fitted to this set of points.
Finally, the starting and ending points are added back in if they are within the tolerance defined. The line is then refitted once more to the new set of points.
The value of fit_type may be BF (Best Fit) or BFRE (Best Fit Recompensate). This determines whether a best fit or best fit with recompensation is done when calculating the line. For a description of Best Fit and Best Fit Recompensate, see "Constructing a Best Fit or Best Fit Recompensate Line"