MATLAB: How to catch warnings

inversematrixwarning

I want to catch Warning: Matrix is close to singular or badly scaled, during a matrix division A/B.

Best Answer

https://undocumentedmatlab.com/blog/trapping-warnings-efficiently

may help with this. Credit to Guillaume from this answer for the link.

Related Solutions

MATLAB: Detect warning and take action

Hello Ioannis,

A common workflow is to use lastwarn in this way:

for ...
    warning('') % Clear last warning message
    ... run code ...
    [warnMsg, warnId] = lastwarn;
    if ~isempty(warnMsg)
        ...react to warning...
    end
end

But you said lastwarn didn't work for you. How did you use it? What do you mean it didn't work? What kind of warnings were you seeing that weren't being picked up?

-Cam

MATLAB: Using “If Warning” as a conditional statement

Hi,

you can use lastwarn to get the last warning:

[warnmsg, msgid] = lastwarn

And than you can compare the msgid from the last warning with the msgid from the warning which you get for a bad matrix.

>> inv([eps eps; eps eps])
Warning: Matrix is singular to working precision. 
ans =
     Inf   Inf
     Inf   Inf
>>  [warnmsg, msgid] = lastwarn
warnmsg =
Matrix is singular to working precision.
msgid =
MATLAB:singularMatrix

So you do something like this in your code:

inv(input_from_user)
[warnmsg, msgid] = lastwarn
if strcmp(msgid,'MATLAB:singularMatrix')
  //warning was thrown, do something
end

Best Answer

Related Solutions

MATLAB: Detect warning and take action

MATLAB: Using “If Warning” as a conditional statement

Related Question