Best Fit Profile

This command processes an input profile that has data points at an interval and creates a best-fit profile with tangents and vertical curves. Each tangent segment in the profile is calculated by the best-fit line least-squares method and each vertical curve is determined by calculating vertical curve lengths between the specified Minimum and Maximum Vertical Curves at the Vertical Curve Resolution and choosing the length with the smallest residuals. The input profile represents the surveyed of the existing profile. One method to create this input profile from survey point data is to use Triangulate & Contour to make a TIN surface from the points and then use Create Profile From Triangulation Surface.In the process options dialog, the Snap Tolerance is the max offset from the point to the profile which is used for finding the best-fit tangent segments. The Minimum and Maximum Vertical Curve values control the range of possible vertical curve lengths. The Vertical Curve Resolution is used to round the resulting length to this value. The Hold Start and End Elevation options keep the original profile elevations for matching an existing road. For Profile Type, Leveling keeps the best-fit profile from going any lower than the original profile, and Milling keeps the best-fit profile from going any higher than the original profile.

The residual for each point is the elevation difference from the point to the best-fit profile. The results are shown in a dialog and you can toggle each point for whether to include in the calculations. Points that are toggled off are not used for calculating the profile but are still used in the residual report. The Remove function removes the point from both calculation and residual reporting. After picking OK on the results dialog, the program prompts for the profile to create with the best-fit results.This example Draw Profile shows the input profile and the best-fit profile along with elevation difference labels between the input profile break points and the best-fit profile.

Prompts

Select Profile to Process Pick the input profile
Best-Fit Profile Options Dialog Set processing options
Best-Fit Profile Results Dialog Review results and toggle points on/off
Select Profile to Write Specify the output profile

Pulldown Menu Location: Profiles->Profile Utilities
Keyboard Command: bestpro
Prerequisite: Profile to processc