Comments on: M-Lint Settings in R2006b

By: Loren

Loren — Mon, 02 Oct 2006 12:24:27 +0000

Great suggesetion, Tim. We happened to have that one already recorded in our list. For the future, the best way to send enhancements to us is to use this link. --Loren

By: Tim Davis

Tim Davis — Mon, 02 Oct 2006 01:31:33 +0000

(This suggestion is for real, not tongue-in-cheek as the “goto” comment was): m-lint should invoke a warning if it sees inv(A)*x, “Multiplying by the inverse is slow and potentially inaccurate; use A\x instead.” I’m amazed at how often I see “inv(A)” misused this way.

By: Tim Davis

Tim Davis — Sun, 10 Sep 2006 13:56:06 +0000

This is very useful. I write a lot of mexFunctions. To document them, I write a companion m-file with all the arguments specified in the first line, ample “help” comments, and then a single statement “error (‘xxx mexFunction not found’)”. The sole purpose of the m-file is to document the mexFunction. mlint constantly complains that my arguments are unused, but they are supposed to be unused. Adding %#ok to the first line is ugly in this case, since the m-file is not for MATLAB to read, but for the end-user to read. The %#ok in the first line distracts the reader. If mlint were smart enough, it could recognize that the first statement in the m-file was “error”, and it should ignore the non-use of any input/output parameters or failure to define output parameters.

In an altogether different state of mind ;-) … we *really* need to *add* another mlint warning. Whenever a goto statement is used mlint should report “warning: go to statement considered harmful” (see http://blogs.mathworks.com/loren/?p=29 and http://www.acm.org/classics/oct95/ for more details). This warning has been noted for almost 40 years … I’m amazed that the warning message has not yet been added to MATLAB.

By: Michael Salloker

Michael Salloker — Fri, 08 Sep 2006 09:28:08 +0000

I like this new featur, because its an easier way getting rid of abnnoying messages like “insert a semi-colon to supress output” without typing %#ok in every line.

Good improvement.

Michael

By: wmar

wmar — Wed, 06 Sep 2006 23:08:45 +0000

I find M-Lint messages to be annoying when I’m in the editor writing m-files, but I find them useful for optimization suggestions when I use the profiler. There’s some rather unsettling about having an m-file that does not have a green light from M-Lint. Like one instance it complains that a variable is not used, but I have to declare it because I need a dummy output so I can get the second output parameter from a function, which I care about.