reading out variable input names where "inputname" gives an empty string

Hi everyone,

i am writing an class with properties and methods to analyse my data

classdef Data < matlab.mixin.Copyable
    properties
        data1 % arrays 500x4 double 
        data2 % arrays 500x4 double
        data3 % arrays 500x4 double
        value
    end
    methods
        function add_data (obj,x,y)
            for m = 1:nargin
                disp(['Calling variable ' num2str(m) ' is ''' inputname(m) '''.'])
            end
            obj.value = x + y;
        end
    end
end

%trying to track which inputs were used in the function
test=Data;
test.add_data(test.data1,test.data3);

--> Result:
Calling variable 1 is 'test'.
Calling variable 2 is ''.
Calling variable 3 is ''.

and now trying to add an log to it, that records all methodes used to be able to later on reproduce the results

the problem i ran into is that using inputname() i dont get out which data was used for x and y in the function, it just returns an empty string

anyone got an idea how to get the names, so in this case

--> Result i would like to get:
Calling variable 1 is 'test'.
Calling variable 2 is 'data1'.
Calling variable 3 is 'data3'.

[Ameer Hamza]

I ran this code and got the correct output, as you mentioned at the end of your question. I defined data1 and data3 as numeric matrices. What is the type of these variables in your code? Please try to run your code after running the following line

clear classes 

[Martin Stiehl]

sry forgot the "test." before the data calls --> coorected

[Stephen23]

"sry forgot the "test." before the data calls"

Neither test.data1 nor test.data3 are variables, ergo they do NOT have variable names.

They are both expressions (actually a type of indexing), the results of which can be allocated to a variable.

[Martin Stiehl]

but they are indexing from the propertys which are variables or?

so shouldnt there be a way to get the name of the variable they are indexing from?

[Stephen23]

"but they are indexing from the propertys which are variables or?"

subsref indexing accesses a part of an array and creates a new array in memory. That new array can certainly be allocated to a variable (which has a name) but often they are used directly without being allocated to a variable (e.g. the input arguments in your example code): the origin of that new array is NOT stored as one of its properties (and there is no way to go back up the entire chain of indexing operations to know any possible variable that the new array might have come from).

"so shouldnt there be a way to get the name of the variable they are indexing from?"

Short of parsing the code yourself, there is no documented way to get all of the names of variables that are used in an expression.

[Martin Stiehl]

then it cant be helped thx anyway for the help