divide by zero warning does not appear in version 2012a

I am testing some examples in a book and am having the following issue. when dividing by zero, 1/0, the book claims that MATLAB generates a Divide by zero warning message. The book claims to use version R2012b, yet when I test this in version R2012a I do not see any error or warnings on the result is Inf as I would expect. Is there a way to 'turn on' this warning in 2012a or is this a case of a bad example in the book I am using?

I have checked the warning state and have found the following

warning The default warning state is 'on'. Warnings not set to the default are

State  Warning Identifier

    off  MATLAB:Debugger:BreakpointSuppressed
    off  MATLAB:JavaComponentThreading
    off  MATLAB:JavaEDTAutoDelegation
    off  MATLAB:RandStream:ActivatingLegacyGenerators
    off  MATLAB:RandStream:ReadingInactiveLegacyGeneratorState
    off  MATLAB:class:DynPropDuplicatesMethod
    off  MATLAB:class:InvalidDynamicPropertyName
    off  MATLAB:mir_warning_unrecognized_pragma
    off  MATLAB:uiflowcontainer:DeprecatedFunction
    off  MATLAB:uigridcontainer:DeprecatedFunction
    off  MATLAB:uitab:DeprecatedFunction
    off  MATLAB:uitabgroup:DeprecatedFunction
    off  MATLAB:uitable:DeprecatedFunction
    off  MATLAB:uitree:DeprecatedFunction
    off  MATLAB:uitreenode:DeprecatedFunction
    off  spblks:block:FromAudioDevice:fromAudioDeviceDroppedSamples
    off  spblks:block:ToAudioDevice:toAudioDeviceDroppedSamples
    off  spblks:system:AudioPlayer:toAudioDeviceDroppedSamples
    off  spblks:system:AudioRecorder:fromAudioDeviceDroppedSamples

Answer 1

[Matt J]

I think it's a bad example in the book. I haven't seen the divide by zero warning in any MATLAB version since 2005.

Answer 2

[Jan]

This is triggered by the line

warning off MATLAB:divideByZero

in the function matlabrc.m, which is called automatically at startup. Either change it there, or better in a user-define startup.m file.

[Ed Davis]

If so how do I turn it on.

the line warning on MATLAB:divideByZero runs but does not change the behavior.

Also, the line warning off MATLAB:divideByZero does not appear in the matlabrc.m file. Nor does any other line with the word divide.

[Kayla McCarty]

Did you ever figure this out?