MATLAB Programming

8 Error Handling
Warning Control
This section covers
• “Warning Statements” on page 8-17
• “Warning Control Statements” on page 8-17
• “Output from Control Statements” on page 8-19
• “Saving and Restoring State” on page 8-22
• “Backtrace and Verbose Modes” on page 8-23
MATLAB gives you the ability to control what happens when a warning is
encountered during M-file program execution. Options that are available
include
• Display selected warnings
• Ignore selected warnings
• Stop in the debugger when a warning is invoked
• Display an M-stack trace after a warning is invoked
Depending on how you set up your warning controls, you can have these
actions affect all warnings in your code, specific warnings that you select, or
just the most recently invoked warning.
Setting up this system of warning control involves several steps.
1 Start by determining the scope of the control you will need for the warnings
generated by your code. Do you want the above control operations to affect
all the warnings in your code at once, or do you want to be able to control
certain warnings separately?
2 If the latter is true, you will need to identify those warnings you want to
selectively control. This requires going through your code and attaching
unique message identifiers to those warnings. If, on the other hand,
you don’t require that fine a granularity of control, then the warning
statements in your code need no message identifiers.
8-16