How do I reset the classification of these points.
You can change the classification manually like in most R object
las$Classification[las$Classification == LASNOISE] <- LASUNCLASSIFIED
# if you prefer a data.table style
las@data[Classification == LASNOISE, Classification := LASUNCLASSIFIED]
I can't find a simply way to view classifications.
You can use plot(las, color = "Classification"), noise point are yellow or you can e.g. filter the noise points filter_poi(las, Classification == LASNOISE).
I am also having trouble updating the classification based on segment_shapes() algorithm results
las <- segment_shapes(las, shp_line(th = 8, k = 15), "linear")
las@data[linear == TRUE, Classification := LASWIRECONDUCTOR]
Otherwise is it possible to tell the function from ch 13 in the lidR textbook to consider all points despite already being classified
It already considers all points, But you can use the filter argument to do not consider all points
I want to use the linear segment_shapes() function to locate powerlines
Looking at your point cloud I hardly believe that you will succeed in segmenting powerline that way. The powerlines are sparse and discontinuous due to low sampling density and thus an eigen decomposition is unlikely to detect linear feature in isolated points.
Best Answer
The LAS Dataset toolbar in ArcMap does not provide any automated classification solutions. The classification that is available through the Profile viewer was meant solely for the facilitation of supervised classification, where you would make a selection and assign the appropriate class code.
In ArcGIS Desktop 10.4 and ArcGIS Pro 1.2, 3D Analyst provides the Classify LAS Ground tool which can be used to obtain a very good classification of ground points on many types of terrain. The freely available 3D Sample Tools package also provides tools for classifying ground and building points using a TIN based methodology. If portions of your data lays in areas where the above-ground returns only contain vegetation, you may want to consider running the Classify LAS By Height tool to assign the vegetation codes based on their height from the ground.