MATLAB: What does the string #ok mean in the code editior

file editorMATLAB

I have a m file that is sprinkled with lines such as…

some code % #ok<NASGU> what does this mean?

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Matlab's code analyzer, mlint, includes a wide range of warning messages about possible problems or inefficiencies in the analyzed m-file.

NASGU indicates the value assigned to variable name might be unused. Putting %#ok<NASGU> in a line of code tells mlint not to worry about this particular issue, on this line. You can see all the warnings as orange little tick marks near the scroll bar of the m-file. Red lines indicate syntax and other errors.

See this page for more information: Check for warnings and errors

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MATLAB: MATLAB Editor Code Analyzer

Add the %#ok pragma at the end of the line:

   x = 2;   %#ok

HTH.

MATLAB: Get the line number of the last warning found

You could shadow the buil-in warning function and grab the stacktrace manually

msgBack  = lastwarn;
warnBack = warning;
traceBack = warning('query', 'backtrace');
warning('on', 'backtrace');
warning('on');
BackTrace = evalc('warning(''Error appeared in:'')');
BackTrace(strfind(BackTrace, char(8))) = [];
BackTrace(strfind(BackTrace, '{'))     = [];
BackTrace(strfind(BackTrace, '}'))     = [];
if strncmpi(BackTrace, 'warning: ', 9)  % Remove initial 'Warning: '
   BackTrace(1:9) = [];
end
BackTrace = strsplit(BackTrace, '\n');
BackTrace(strncmp(BackTrace, '> ', 2)) = [];  % 1st line: '> SuError...'
if length(BackTrace) == 1
   BackTrace{2} = '  Command line';
end
% Restore original state of WARNING:
if ~isempty(traceBack)
   warning(traceBack);
end
warning(warnBack);
lastwarn(msgBack);

Now you have to replace all calls of builtin('warning') by builtin('warning') and care for the outputs.

But this is such ugly and it would be horrible, if a programming error conceals important warnings. Therefore I would never use this for serious code. (I use this code snippet to get a stack-trace in a user-defined Error class only.)

Think about using another method than the stacktrace to track the warning. What about parsing the output to the command window? See FEX: CmdWinTool for a method to get the text from it.

Best Answer

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MATLAB: MATLAB Editor Code Analyzer

MATLAB: Get the line number of the last warning found

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