Accessing a coupled array's du_dot_du

[NateAM]

I'm having some trouble accessing a coupled array's _du_dot_du variable. In my header I define

myClass.h

...
const VariableValue & _dv_dot_dv;
...

and in the source file I define

myClass.C

InputParameters myClass::validParams( ){
    ...
    params.addRequiredCoupledVariable( "v", "my docstring" );
    ...
}

myClass::myClass( const InputParameters & parameters )
    : myBaseClass( parameters ),
    ...
    _v( coupledArrayValue( "v" ) ),
    _v_dot( coupledArrayDot( "v" ) ),
    _dv_dot_dv( coupledDotDu( "v" ) ),
    ...{
}

When I run this, I get the moose error:

*** ERROR ***
Variable 'v' is of a different C++ type than you tried to fetch it as.

I haven't seen any class that tries to get coupledArrayDot so is this functionality not implemented yet? Would a workaround be to use _du_dot_du? What kind of limitations would that impart on my class?

[GiudGiud]

Hello

I would worry about this one coupledDotDu( "v" ) which is likely not for Array variables (Array is not in the name)

can you see if it runs without that one?
You would then need to implementcoupledArrayDotDu( "v" )

[NateAM]

Sorry, I was unclear! Yes, it's the coupledDotDu that fails for me and my subroutine works without it. I mentioned looking for coupledArrayDot because I was hoping to find someone else who had tried that.

I guess I should follow what was done to implement this in Coupleable::coupledArrayVal or Coupleable::coupledArrayDot and then try and add that method to my class. Does that sound about right?

[GiudGiud]

add it to Coupleable.C and then contribute it to MOOSE ;) ?

you can follow these routines. I think the regular variable coupledDotDu will also be a good inspiration

[NateAM]

add it to Coupleable.C and then contribute it to MOOSE ;) ?

Yeah, that seems like the better option! I'll try and get this in and submit a pull request shortly. I'll need coupledArrayDotDotDu too so that should be included soon as well.