[GustavGans]

Hey there,

maybe you can help me with the following problem I'm currently dealing with:

In my solver, I defined a volScalarField border which only contains the values 0 and 1.
Now I would like to set the values of a volVectorField U to zero, but only in the cells where the value of border is 1.

So far, I'm doing this with a forAll-loop, as follows:

forAll(U,i)
{
    if(border[i] == 1)
    {
        U[i].component(0) = 0;
        U[i].component(1) = 0;
        U[i].component(2) = 0;
    }
}

but since this is an expensive operation, I would like to avoid this. Instead, I would like to use a Matrix-operation, something like (This is only Pseudo-Code, just to show my plan)

if(border == 1)
{
    U = 0;
}

Any ideas?