Feature request: function retrieve_flightlines to update LAS header

[mbedward]

Thank you for the brilliant package.

The docs for the function retrieve_flightlines state:

An attribute flightlineID is added in the LAS object.

This implied to me that the header would be updated as per the add_lasattribute function so that the flightlineID column would be written to file by a subsequent call to writeLAS. However, looking at the code for retrieve_flightlines that's not the case, Would it be possible to add this behaviour to the function or is there some reason why it is preferable to leave the header untouched?

Presently, I call add_lasattribute(las, name = 'flightlineID', desc = "Flight line ID") to accomplish this, but often forget.

[Jean-Romain]

retrieve_flightlines() is an old function created before the package have half of the current capabilities. FlightlineID should actually be recorded in the core attribute PointSourceID without extra attribute. retrieve_flightlines() should therefore be retrieve_pointsource() or something like that. This is why I never changed retrieve_flightlines(). My goal with this function is to create a new one that work better by updating PointSourceID and capable of processing a LAScatalog. But I did not find a way to successfully attribute consistent IDs to each flightline spread in on different files.

So I wont do what your are asking because this is not the way it should work. However considering the way it currently works your solution is the good one. Maybe las$PointSourceID = las$flightlineID is better and simpler.

[mbedward]

That all makes sense - thank you.