How to create a log file of output regardless of whether program finishes running?

How can I record a log-file of Matlab console output even if my program doesn’t finish running because of errors? I used “diary on” and “diary off” to log the output, but since the program broke out prematurely, “diary off” was not run, and therefore the log file was not created. An example is below. In this example, the fmincon stops when some parameters travel to certain regions. Once the whole program stops, "diary off" doesn't get to run, and I have no output log file. The key is that I still want to save the parameters and function values from the past iterations of fmincon into a log file, and I don’t want to manually run “diary off” every time. Does anyone have a solution to this?

clear;
diary_name = strcat(datestr(now),'_diary.txt');
diary_folder = pwd; 
diary(diary_name)
disp([datestr(now), ' Main Program'])
global theta1 predicted gmmresid
load('outervariables.mat');
theta1 = zeros(size(outstruct.x1, 2),1);
spmd
    data = load(['dataworker' num2str(labindex) '.mat']);
end

theta2 = sig;

fun = @(theta2)gmmobj(theta2, outstruct);

maxiter = 1000;
options = optimoptions('fmincon', ...
    'SpecifyObjectiveGradient',true, 'Display', 'iter-detailed', ...
    'MaxFunctionEvaluations', maxiter, ...
     'OptimalityTolerance', 1e-5, 'FunctionTolerance', 1e-5);

theta20 = theta2;

lb = [0; 0; 0 ; 0; 0; -6; 0; 0; 0.00001; -5; 0];
ub = [1; 0.1; 0.1; 0.2; 0.5; 0; 4; 0.5; 0.1; 0; 4];

disp('IVs for theta2 are not demeaned')
disp(['Minimizing GMM objective function with a max of ', num2str(maxiter), ' interations returns: '])

tic
[x, fval] = fmincon(fun, theta20, [], [], [], [], lb, ub, [], options);
toc

disp('theta2 estimates are')
x

diary off;
save('blpresults.mat', 'x', 'fval', 'predicted', 'gmmresid', 'theta1');

Answer 1

[Chunru]

Consider use error catch:

clear;
try
    diary_name = strcat('_diary.txt');
    diary_folder = pwd; 
    diary(diary_name)
    disp([datestr(now), ' Main Program'])
    global theta1 predicted gmmresid
    load('outervariables.mat');
    theta1 = zeros(size(outstruct.x1, 2),1);
    spmd
        data = load(['dataworker' num2str(labindex) '.mat']);
    end
    theta2 = sig;
    fun = @(theta2)gmmobj(theta2, outstruct);
    maxiter = 1000;
    options = optimoptions('fmincon', ...
        'SpecifyObjectiveGradient',true, 'Display', 'iter-detailed', ...
        'MaxFunctionEvaluations', maxiter, ...
         'OptimalityTolerance', 1e-5, 'FunctionTolerance', 1e-5);
    theta20 = theta2;
    lb = [0; 0; 0 ; 0; 0; -6; 0; 0; 0.00001; -5; 0];
    ub = [1; 0.1; 0.1; 0.2; 0.5; 0; 4; 0.5; 0.1; 0; 4];
    disp('IVs for theta2 are not demeaned')
    disp(['Minimizing GMM objective function with a max of ', num2str(maxiter), ' interations returns: '])
    tic
    [x, fval] = fmincon(fun, theta20, [], [], [], [], lb, ub, [], options);
    toc
    disp('theta2 estimates are')
    x
catch
    disp('Error occurs.')
end
diary off;
save('blpresults.mat', 'x', 'fval', 'predicted', 'gmmresid', 'theta1');

[Steven Lord]

You could use a try / catch block. Another approach would be to use onCleanup objects. Their sole purpose is to run code when they are deleted. This can be because the function in which they existed exited normally, or it could be because the function threw an error.

demoOnCleanup()

Counting up by twos:
Next number: 1
Next number: 3
Next number: 5
Next number: 7
2

Error using solution>demoOnCleanup (line 8)
Stopping at 7!

function demoOnCleanup
disp('Counting up by twos:')
displayTwo = onCleanup(@() disp('2')); % no display yet
for k = 1:2:11
    fprintf("Next number: %d\n", k)
    if k == 7
        error('Stopping at 7!')
    end
end
end

[Claire Fang]

Thanks a lot. It worked!

[Mitesh]

Matlab has grate build in function call 'oncleanup'. Loop up it's help.

Whenever there is an error, you can call it to close out diary, files or even close communication with equipment whenever there is an error.

I use it alot. And it is very help. Except for when it come to diary off....it's bit tracky and haven't quite figure out how to use it. i use a lot for closeing out Files and GPIB/USB communication on error.