Editing .mat file in matlab

I am struggling to edit the ActionInfo in DQN_agent_Sell_Trained.mat file. I have tried to use the examples at Access and change variables in MAT-file without loading file into memory - MATLAB (mathworks.com) but was not successful. I have tried

ActionInfo_Sell=some filetype
DQN_agent_Sell_Trained = matfile('DQN_agent_Sell_Trained.mat','Writable',true);
DQN_agent_Sell_Trained.ActionInfo=ActionInfo_Sell;

However, when I run the code, a new ActionInfo variable is added instead of overwriting the ActionInfo with ActionInfo_Sell. Any clue on how to solve my problem? I have attached the file. Or to make my question simple, how do I replace or edit ActionInfo variable within the DQN_agent_Sell_Trained.mat file?

Answer 1

[Image Analyst]

Why do you not want to read it into memory? Why not simply do

% Load mat file into a structure.
s = load('DQN_agent_Sell_Trained.mat');
% Get one of the variables that we want to alter.
DQN_agent_Sell_Trained = s.DQN_agent_Sell_Trained
% Then modify DQN_agent_Sell_Trained somehow. 
% Then save it back out:
save('DQN_agent_Sell_Trained.mat', 'DQN_agent_Sell_Trained', '-append');

[Ivan Tadiwanashe Chuma]

The part of modifying DQN_agent_Sell_Trained is the one I need help with. Also how can I modify DQN_agent_Sell_Trained considering its read-only?

[Image Analyst]

I have no idea how you want to modify it. How about you just set it equal to 1? If not, then what do you want to do to it?

If the file is readonly and you want to change it, you should use the operating system to remove the readonly property from the file.

[Ivan Tadiwanashe Chuma]

Lets say I want to set ActionInfo = 1, how do I do it? I have tried

s = load('DQN_agent_Sell_Trained.mat');
DQN_agent_Sell_Trained = s.DQN_agent_Sell_Trained
DQN_agent_Sell_Trained.ActionInfo = 1 %Just an example

But I am getting the notification error that the file is read-only. Kindly assist.

[Image Analyst]

If the file is readonly and you want to change it, you should use the operating system to remove the readonly property from the file.