[Verse]

Hello, I'd like a way to access the pressure parameter in my test case through OpenFOAM syntax. So far, the answers I've seen only refer me to this method:

const volScalarField & p = Foam::fvPatchField<Type>::db().lookupObject<volSca larField>("P");

But I received the following error:

error: invalid use of ‘this’ in non-member function
const volScalarField& p = this->db().lookupObject<volScalarField>("P");

Any idea what's going on? Thank you!

[Jerryfan]

Hi Verse,


where do you use this line of code? Is it in the main function? If it is, you can do it this way

const volScalarField & p = mesh.lookupObject<volSca larField>("P");

since pressure field is registered to mesh at the time of construction. Hope this can work for you.

[Verse]

Hi Jerry, thank you for the answer, it works terrifically.

I was wondering if I could do the same with a different file of a different type, namely pointMotionU?

I tried the following and I seem to have run into a different error...

const pointVectorField& MotionU = mesh.lookupObject<pointVectorField>("pointMotionU");

error: forward declaration of ‘class Foam::pointMesh’
 class pointMesh;

[Jerryfan]

Hi Verse,



I think the problem is because of pointVectorField. Try to replace it with vectorField. It might work.

[Verse]

Hi Jerry, the solution turned out to be a bit more complicated, but doing this helped solve the problem:

	pointVectorField& MotionU = const_cast<pointVectorField&>
	(
		mesh.objectRegistry::lookupObject<pointVectorField>
		(
			"pointMotionU"
		)
	);

Hopefully future users can see this post to avoid my mistake.

Thank you for the help!

[Jerryfan]

Hi Verse,

You are right. The const_cast has to be added in front to cast away the constness as lookupObject returns const type variable.

const Type& Foam:bjectRegistry::lookupObject(const word& name) const