[Insight-users] Re: Stopping registration using metric value

[Luis Ibanez]

Hi Radhika,


   "Knowing constancy is Insight
    Not knowing constancy leads to disaster"

                      Tao Te Ching,XVI, Lao Tsu


----

ITK considers a double role for the Observers.

Those who quietly "observe" another ITK object
without disturbing it, and those more "interven-
tionalist" observers who take the liberty of
changing the state of the object they observe.

For this reason you will find that the Observer
interface of the itk::Command class has two different
Execute() methods. One with const interface and other
with non-const interface.


A) Non-Const (Quantum-mechanics observers):

void Execute(Object *caller, const EventObject & event );


B) Const (Newtonian observers):

void Execute(const Object *caller, const EventObject & event );


When you plan to alter the state of the object that
you are observing, you should implement this action
in the Execute() method with non-const interface.

The compiler errors that you are getting are the result
of putting your code in the "const" Execute method and
still attempt to call non-const methods of the optimizer.


Please put your code in the non-const method.



Regards,


     Luis



--------------------------------
Radhika Sivaramakrishna wrote:

> Hi Luis,
> 
> As you had indicated in a previous post, I tried to include a statement 
> like below in the Evaluate function of my
> 
> command observer.
> 
>  
> 
> if (optimizer->GetValue() < 30)
> 
>          optimizer->StopOptimization();
> 
>  
> 
>  
> 
> However, I got the error below.
> 
>  
> 
>  
> 
> Building object file Registration3D.o...
> 
> /export/jfs/rsivaram/Registration/Registration3D.cxx: In member function
> 
>    `virtual void CommandIterationUpdate::Execute(const itk::Object*, const
> 
>    itk::EventObject&)':
> 
> /export/jfs/rsivaram/Registration/Registration3D.cxx:57: passing `const
> 
>    itk::VersorRigid3DTransformOptimizer' as `this' argument of `void
> 
>    itk::RegularStepGradientDescentBaseOptimizer::StopOptimization()' 
> discards
> 
>    qualifiers
> 
> make[1]: *** [Registration3D.o] Error 1
> 
>  
> 
>  
> 
> Is this just a casting problem, or something else?
> 
>  
> 
>  
> 
> Thanks
> 
> Radhika
> 
>  
> 
> -----------------------------------------------------
> 
> Confidentiality Notice.
> 
> This email message is for the sole use of the intended recipient(s) and 
> may contain confidential and privileged information. Any unauthorized 
> review, use, disclosure or distribution is prohibited. If you are not 
> the intended recipient, please contact the sender by reply email and 
> destroy all copies of the original message. If you are the intended 
> recipient, please be advised that the content of this message is subject 
> to access, review and disclosure by the sender's Email System Administrator.
>