Development Environment

Running an M-File with Breakpoints

After setting breakpoints, run the M-file from the Command Window or the Editor/Debugger.

For the example, run collatzplot for the simple input value, 3, by typing in the Command Window

• collatzplot(3)
  

The example, collatzplot, requires an input argument and therefore runs only from the Command Window and not from the Editor/Debugger.

Results of Running an M-File Containing Breakpoints.   Running the M-file results in the following:

• The prompt in the Command Window changes to

• K>>
  

• indicating that MATLAB is in debug mode.

• The program is paused at the first breakpoint, which in the example is line 10 of collatzplot. This means that line 10 will be executed when you continue. The pause is indicated in the Editor/Debugger by the green arrow just to the right of the breakpoint as shown here.

  

• If you use debugging functions from the Command Window and do not have the file you are debugging open in the Editor/Debugger, the line at which you are paused is displayed in the Command Window, if you do not have the Editor/Debugger preference for Automatically open files while debugging selected. For the example, it would show

  • 10  plot_seq = collatz(m);
    

• The function displayed in the Stack field on the toolbar changes to reflect the current function. The call stack includes subfunctions as well as called functions. If you use debugging functions, use dbstack to view the current call stack.
• If the file you are running is not in the current directory or a directory on the search path, you are prompted to either add the directory to the path or change the current directory.

While in debug mode, you can set breakpoints, step through programs, examine variables, and run other functions.

Setting Breakpoints

Stepping Through an M-File