Detect errors on GUI

Hello, I want to make an .exe program using guide. I designed everything.

I want to detect the errors on my code because of the input values. For example for the input value if I input an absurd value (high or low) it gives "Index exceeds matrix dimensions" error on the command window. Now i can see that. But when i create .exe how can I understand the error? Is it possible?

Or, if I get an any kind of error, how can i write "NaN" or "0" to the results section (edit texts).

Thank in advance.

Answer 1

[Walter Roberson]

You should be coding in such a way that you never get those index errors: your code should be testing the user input range or calculated range before doing the indexing.

In the meantime, you should be putting try/catch clauses in your code to detect and display errors that do occur.

try
   output = myfunction();
catch ME
   output = nan;
end

[HSukas]

I'm sorry, i didn't understand where should i put that on the gui? Should i put callback of the run (calculation) button or the opening part?

[Walter Roberson]

At the moment, you have some code that is the approximate form

   output = myfunction();

or

   ... series of statements
   output = whatever result

but the function myfunction() or the series of statements can fail (because you are not checking your results properly before indexing.)

You can protect against the failure by rewriting your code into the form

try
   output = myfunction();
catch ME
   output = nan;
end

or

try
     ... series of statements
     output = whatever result
catch ME
     output = nan;
end

as appropriate.

You can put try/catch blocks around any series of statements or function calls that might fail with an error() and where you want to have the error smoothly caught instead of causing the program to end.

[HSukas]

Thank you!