MATLAB: How to use a method to assign a structure to a class property

classmethodobjectsoopstructures

I'm new to Matlab, and am trying to create a class definition that will allow me to dynamically assign structured property variables to an object. I've defined the following class:
 classdef WAVE
     %UNTITLED5 Summary of this class goes here
     %   Detailed explanation goes here
     properties
         s %string structure
         v %variable structure
     end
     methods
         function WAVE = newVar(WAVE,NAME,VALUE)
            % test if variable value is text or number
            if ischar(VALUE)
                % if text, then store as given variable name in the "s"
                % structure

                WAVE.s.(NAME) = VALUE;
            else
                % otherwise store as a given variable name in the "v"
                % structure
                WAVE.v.(NAME) = VALUE;
            end
         end
     end
 end
The idea here is to create the object (ie, object1 = WAVE) but then be able to assign a new property to it as such:
object1.newVar('name','My Object')
When this method is run, I'd like to have object1 updated so its "s" property (that for string variables) becomes a structure that has a new entry "name" which contains the data "My Object".
In this manner, the idea is to be able to get this object's name at a later point by running the following:
object1.s.name
Currently the above method works, but I have to reassign the output to the original object, such as the following:
object1 = object1.newVar('name','My Object')
Is there any way to implement this as a method so the method directly alters the object's property and does not need to be reassigned? I think there may be some issue with the use of "(NAME)" in the class method, since I can use "WAVE.v = VALUE" and it works just fine; however, this simply changes the "v" property to a single value and does not let it become a structure (my intended property type).
I should add that I can create an object from this class by the following command:
object1 = WAVE;
…and then properly assign structures to the "s" and "v" properties in the following manner:
field = 'name';
object1.s.(field) = 'My Object';
This ends up working as expected, but I cannot seem to get it to work when called within the methods block of the class definition.

Best Answer

Try this script:
    w = WAVE();
    w.newVar('name','My Object');
    field = 'name2'; 
    w.s.(field) = 'My Object 2';
    w.s.name
    w.s.name2
It prints
    ans =
    My Object
    ans =
    My Object 2
where
     classdef WAVE < handle
         properties
             s %string structure
             v %variable structure
         end
         methods
             function WAVE = newVar(WAVE,NAME,VALUE)
                % test if variable value is text or number
                if ischar(VALUE)
                    % if text, then store as given variable name in the "s"
                    % structure

                    WAVE.s.(NAME) = VALUE;
                else
                    % otherwise store as a given variable name in the "v"
                    % structure
                    WAVE.v.(NAME) = VALUE;
                end
             end
         end
     end
.
In response to comment regarding value class:
  • Edit the first line of the class definition file; replace classdef WAVE<handle by classdef WAVE
  • Run this modified script
    w = WAVE();
    w = w.newVar( 'name', 'My Object' );
    field = 'name2'; 
    w = w.newVar( field, 'My Object 2' );
    w.s.name
    w.s.name2
which shall return
    ans =
    My Object
    ans =
    My Object 2
    >>
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