如何抑制GNU八度音程中的警告

Question

I am using Octave version 3.4.3, and I get this warning:

warning: fmincg.m: 
possible Matlab-style short-circut operator at line 104, column 20

I know why this warning occurs, I just want to make the warning not appear on screen when run.

I know I can suppress ALL warnings by putting this command at the top of my octave program:

warning('off','all');

But that disables all warnings which is bad form. How to disable only this one?

Answer 1

Disable warnings by warning type in GNU Octave:

See the list of warnings and their warning id's and names here in section: '12.2.2 Enabling and Disabling Warnings'. https://octave.sourceforge.io/octave/function/warning_ids.html

The warning names and id's are listed with octave command:

help warning_ids

Put this command in your octave program before the warning occurs:

warning('off', 'Octave:possible-matlab-short-circuit-operator');

or disable all warnings with

warning('off', 'all');

Note: If your warning is thrown by the octave interpreter itself before your script is run, then you'll have to take a different approach. For example use octave yourfile.m 2>/dev/null which also has the unfortunate side effect of redirecting the stderr of both the octave engine and your script.

Certain warnings terminate the process, and can't be suppressed, they must be remedied:

Like this one:

warning: function /home/el/octave/multicore-0.2.15/gethostname.m 
         shadows a built-in function

To fix this, rename /home/el/octave/multicore-0.2.15/gethostname.m to /home/el/octave/multicore-0.2.15/gethostname_backup.m. And the warning goes away. It's a bug in the software where two files have the same name, so the program doesn't know which one to use.

Answer 2

To find out the ID of your warning, just issue

[text, id] = lastwarn()

directly after the warning occurs. id now contains the id of the warning, which can be used to switch it off:

warning('off', id)

Answer 3

Make your changes persistent in two easy steps:

1. become root

2. append command to the file (/usr/share/octave/site/m/startup/octaverc), which will execute any Octave commands at startup.

   echo "warning('off','Octave:shadowed-function')" >> /usr/share/octave/site/m/startup/octaverc

I also like to persitantly autoload all packages:

echo "pkg load all" >> /usr/share/octave/site/m/startup/octaverc

Note: Follow this order, otherwise any shadowed-function warnings you get from loading all packages will still appear.

your file should now contain

warning('off','Octave:shadowed-function')
pkg load all

Thanks to Gunther Struyf , for telling us how to turn off shadowed function warnings (above). Reference: https://wiki.archlinux.org/index.php/Octave