How can I "watch" variables using the MATLAB Debugger?

I would like to set "watches" on variables while using the MATLAB Debugger. In particular, I would like to configure the debugger to break when the variable reaches a certain value or exceeds a certain range.

Answer 1

[MathWorks Support Team]

In order to "watch" a variable, you can set a conditional breakpoint to stop when a certain condition is met. You can select a conditional break point interactively from the editor tab in MATLAB R2012b or newer, or through the command line.

For example, to stop in debug mode when ii is equal to 25, in the file "watched.m", which consists of the following:

for ii = 1:100

      disp(ii)

end

You could run:

dbstop in watched at 2 if (ii == 25)

For more information, please see the documentation for dbstop:

https://www.mathworks.com/help/matlab/ref/dbstop.html

Answer 2

[Marshall]

You can set conditional breakpoints to stop when a variable meets some condition that you specify: Where breakpoints are shown right click and select "set conditional breakpoint" or right click on an existing breakpoint and choose "set/modify condition". Then type an expression that will be evaluated to trigger the breakpoint, e.g. a>100.