MATLAB Programming

Program Development
line and examining the results of each operation performed. You have the
choice of operating the debugger from the Editor window that displays your
program, from the MATLAB command line, or both.
The Debugging Process
You can step through the program right from the start if you want. For longer
programs, you will probably save time by stopping the program somewhere in
the middle and stepping through from there. You can do this by approximating
where the program code breaks and setting a stopping point (or breakpoint)
at that line. Once a breakpoint has been set, start your program from the
MATLAB command prompt. MATLAB opens an Editor/Debugger window (if it
is not already open) showing a green arrow pointing to the next line to execute.
From this point, you can examine any values passed into the program, or the
results of each operation performed. Youcanstepthroughtheprogramline
by line to see which path is taken and why. You can step into any functions
that your program calls, or choose to step over them and just see the end
results. You can also modify the values assigned to a variable and see how
that affects the outcome.
To learn about using the MATLAB Debugger, see Debugging and Improving
M-Files in the Desktop Tools and Development Environment documentation.
Type help debug for a listing of all MATLAB debug functions.
For programming tips on how to debug, see “Debugging” on page 12-22.
Cleaning Up the Program
Even after your program is bug-free, there are still some steps you can take
to improve its performance and readability. The MATLAB M-Lint utility
generates a report that can highlight potential problems in your code. For
example, you may be using the elementwise AND operator (&) wherethe
short-circuit AND (&&) is more appropriate. You may be using the find
function in a context where logical subscripting would be faster.
MATLAB offers M-Lint and several other reporting utilities to help you
make the finishing touches to your program code. These tools are described
under Tuning and Refining M-Files in the Desktop Tools and Development
Environment documentation.
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