[gsam]

For a particular boundary, I need to code the gradient variation as a boundary condition. So that gradient is actually a function of the x coordinate. For every point, this gradient will vary. I've tied to code this with the help of codedMixed. But it doesn't work. I've given my expression below....if it is possible, could someone correct this?
Pressure_outlet
{
type codedMixed;
name logarithamicvoltage1;
refValue uniform 0;
refGradient uniform 0;
valueFraction uniform 0;

code
#{

const fvPatch& boundaryPatch = this->patch();
const vectorField& Rf = boundaryPatch.Cf();
const label& patchLabel = boundaryPatch.index();
scalarField& Field = *this;
forAll(Rf, facei)
{
const scalar p = Rf[facei].x();
const scalar q = Rf[facei].y();
Field[facei]=1645*(-0.1103)*((1/pow(876.818+pow(p/9.004095e-5,2),0.5)) + (1/pow(999.262+pow(p/9.004095e-5,2),0.5)));

}
this->refGrad()=Field ;

#};
}