is there any way to pause the code if there exist an imaginary variable?

I want matlab to stop if an imaginary number produced any where in the code. I can make an if condition for specific variable but is it possible to make code stop on every where imaginary number is made?

[Adam Danz]

Could you elaborate on the larger goal? It sounds like we may be sneaking into an XY problem.

Answer 1

[Walter Roberson]

At any particular location, you can insert a conditional breakpoint with the condition

any([whos().complex])

However, it is not possible to put in a breakpoint that stops as soon as any variable is assigned a complex value, and it is not possible to put in a breakpoint that stops as soon as any expression is assigned a complex value.

There is no call such as dbstop if complex

Answer 2

[dpb]

While I've not tried it, the following should work if you can arrange the conditions needed. The first one may be the kicker in that the variable w will only know of those variables that exist in the workspace when it is executed...any that come later won't be known.

Perhaps preallocation of everybody would serve -- something like having an

IMPLICIT NONE

statement in a Fortran code module; require a declaration for everything of interest. One would presume things like loop indices, etc., would not be of interest/need to be covered.

w=whos;   % create the variable in your function--it will have to execute after all variables exist

Then set the expression as

dbstop in file if any([w.complex])

The real kicker is, of course, that you have to have the variable w recreated continuously -- it won't do for it to be static.

[Walter Roberson]

dbstop in FUNCTIONNAME if any([whos().complex])

or

dbstop in FILENAME if any([whos().complex])

both have the effect of putting the condition on the first executable line of the function.

[dpb]

Good catch, Walter...shoulda' thunk of it...

Answer 3

[Image Analyst]

I don't think anywhere within the program, but you might be able to check certain specific variables at certain specific locations in the code, like

squareRoot = sqrt(someNumber); % Some operation that might produce a complex number.
% See if it's complex.
if imag(squareRoot) ~= 0
    % If the imaginary part is not zero, then it's complex, and we need to warn the user.
    uiwait(warndlg('Hey!!! The "squareRoot" variable is complex!!!'));
end