How do I write a .LAS file from .mat data?

I am trying to save XYZ data as a .LAS file to use in another program, but I keep getting the following error.

I am using the LASwrite function (see https://www.mathworks.com/matlabcentral/fileexchange/66033-lasio for the tool download).

The error message:

Dot indexing is not supported for variables of this type.

Error in LASwrite (line 106)

guid_1 = s.header.project_id_1;

Error in SurveyProcessing (line 83)

LASwrite(drone, 'D:\Drone LAS and tif files\2021.03.21\drone.las');

How do I fix my script? I'm not sure if the struct needs to be formatted differently, or is there is a better method entirely.

Thanks!

% first put data into a struct
drone.header = {}; % I've tried running it with and without this header 
drone.X = droneX;  % X Y and Z data are 890723x1 doubles representing stateplane coordinates and elevation
drone.Y = droneY;
drone.Z = droneZ;

% then use LASwrite (need tool download)
LASwrite(drone, 'D:\Drone LAS and tif files\2021.03.21\drone.las'); 

Answer 1

[Walter Roberson]

guid1 = uint32(0);   %32 bit
guid2 = uint16(0);   %16 bit
guid3 = uint16(0);   %16 bit
guid3 = blanks(8);  %unsigned char 8 bytes

drone.header = struct('project_id_1',  guid1, 'project_id_2', guid2, 'project_id_3', guid3, 'project_id_4', guid4);

Under at least some circumstances, the header might perhaps also require fields named

• offset_to_evlr
• number_of_evlr
• n_points_by_return
• n_points_by_return_extended