Variable change should not affect during loop execution?

How should I not update the variable if its value is changed from dashboard during execution? For example:

If a variable value is 1 then throughout the time of execution of code it should be 1. If its value is changed from dashboard to 2 in between, then the loop should first complete its execution using the previous value and once it has completed then only the variable value should be 2 and then rest of the execution should be done. Basically, what I am trying to do is, changing variable value in between should not affect the loop, only after it has completed its execution, then it should take the new value. Can anyone guide me on how should I do it?

[Mohammad Sami]

You can just assign the value to a temporary variable and use the temporary variable in your loop.

[Sanjeet Kulkarni]

Using the assignin function?

[Sanjeet Kulkarni]

Eg: Two variables a and b in simulink. Simulink calls one matlab function while executing.

Function
if  (condition)
    output = b;
else (condition)
    output= a;
end

If value is changed of a and b, the change should be reflected after it has come out of the if loop. What other condition can I put in with if loop or any other way by which it can be done?

Answer 1

[Walter Roberson]

Function
  for variable = 1 : number_of_iterations
    original_a = a;
    original_b = b;
    
    if  (condition)
        output = original_b;
    else (condition)
        output= original_a;
    end
  end

If a or b are changed through the dashboard any time between copying them to the original_* variables and the end of the loop iteration, then the old version wil be used until the next loop iteration.

If it is important that the user should be able to change the value with the dashboard between the time of the "for variable" loop moving to the next iteration, and the point where this code copies the variables, then a different approach would need to be taken.

[Sanjeet Kulkarni]

I feel a different approach should be taken.

for variable = 1 : 100

original_a = a;

original_b = b;

if variable < 50

output = original_b;

else

output= original_a;

end

end

Using this, if a=1, b=1 and if I change a and b values before variable reaches 100 the output reflects this change.

What I am trying to do is, if values of a&b are changed to 2 before variable reaches 100, the for loop should execute completely and when variable starts again from 1 after reaching 100, that time the output should reflect the changes and it should change from 1 to 2.