about functions of boundary condition:valueInternalCoeffs,alueBoundaryCoeffs,g radient
 

dear all,
I just want to find the background formula about these functions, can anyone help me? i donot know which part of the formala should use as the input for this function. and the influence to the equation Ax=b

can anyone help me?thanks
have a good day.


//- Return the matrix diagonal coefficients corresponding to the
// evaluation of the value of this patchField with given weights
virtual tmp<Field<Type> > valueInternalCoeffs
(
const tmp<scalarField>&
) const;

//- Return the matrix source coefficients corresponding to the
// evaluation of the value of this patchField with given weights
virtual tmp<Field<Type> > valueBoundaryCoeffs
(
const tmp<scalarField>&
) const;

//- Return the matrix diagonal coefficients corresponding to the
// evaluation of the gradient of this patchField
virtual tmp<Field<Type> > gradientInternalCoeffs() const;

//- Return the matrix source coefficients corresponding to the
// evaluation of the gradient of this patchField
virtual tmp<Field<Type> > gradientBoundaryCoeffs() const;