Save vector to class properties

Greetings,

I am trying to build a class that would extract information from .csv files and save these information to the properties of the class. Attached is the example of the file.

Here are my code:

classdef post_processing
    properties
        data_folder = 'path\path'
        filename
        time
        voltage
        norm_voltage
        record_length
        state_level_high
        state_level_low
    end
    methods
        function extract_info(obj)
            addpath(obj.data_folder);
            filename = 'test.csv';
            data = readmatrix(filename);
            horizontal_offset = data(6,2); %seconds
            sample_interval = data(2,2);%seconds
            record_length = data(1,2); %points
            time = data(:,4)-horizontal_offset; %seconds
            voltage = data(:,5); %volt
            norm_voltage = data(:,5)/max(data(:,5));%arb. units 
            
            obj.time = time;
            obj.voltage = voltage;
            obj.norm_voltage = norm_voltage;
            obj.record_length = record_length;
        end
    end    
end

I called my script:

test = post_processing;
extract_info(test);
test

give output

I do not know why my properties are not updated when I called my extract_info function.

Thanks for the help.

Answer 1

[Walter Roberson]

            addpath(obj.data_folder);
            filename = 'test.csv';

Bleh. You should use

            filename = fullfile(obj.data_folder, 'test.csv');
            

With regards to your main question: you are not deriving from handle class, so you are defining a value class. You need to assign the output of the methods over top of the object:

            obj = extract_info(obj);

[novelphy]

filename = fullfile(obj.data_folder, 'test.csv');

Neat.

That works. Thanks!