MATLAB: How to stop on a variable getting a specific value

breakpointconditional breakpointdebugMATLAB

I have a variable that can change its value in multiple locations within a long function.

For debugging purposes I want to stop-in-debug once this variable gets a specific value.

I could go throughout the code and set a conditional breakpoint in each line it can happen, but I wonder, if there is a way to set a "global" conditional breakpoint?

Best Answer

dbstop in file at if expression

is best you can do I think...you don't have to manually insert the breakpoint at every line but would have to get the line numbers and put into a little script to run...a little grep utility could possibly be invoked to build/retrieve the lines in the m-file with an assignment to the subject variable name???

ADDENDUM:

I've long thought the debugger should have a watch facility besides...

Related Solutions

MATLAB: List of varialbes used in a m file

No, matlab does not have a way to get the list of variables in a script. Possibly, you could cobble something together using undocumented functions such as mtree but that would be a lot of work for something that you shouldn't have to do.

In my opinion, you would be better off rewriting the code. It sounds like it is written as one monolithic huge script which is an extremely bad design. The code should use functions to subdivide tasks. Any single script/function that holds 100s of variables at once is a maintenance nightmare.

MATLAB: How to “watch” variables using the MATLAB Debugger

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

Best Answer

Related Solutions

MATLAB: List of varialbes used in a m file

MATLAB: How to “watch” variables using the MATLAB Debugger

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