elliptic::analytic_data::Background Class Reference

Subclasses supply variable-independent background data for an elliptic solve. More...

#include <Background.hpp>

Detailed Description

Subclasses supply variable-independent background data for an elliptic solve.

Examples for background fields are a background metric, associated curvature quantities, matter sources such as a mass-density in the XCTS equations, or just a source function $f(x)$ in a Poisson equation $\mathrm{\Delta }u=f(x)$.

Subclasses must define the following compile-time interface:

• They are option-creatable.

• They define a variables function that provides the fixed-sources in the elliptic equations (see elliptic::protocols::FirstOrderSystem). The function must have this signature:

    tuples::TaggedTuple<Tags::FixedSource<ScalarFieldTag>> variables(  // NOLINT
        const tnsr::I<DataVector, 1>& x,
        tmpl::list<Tags::FixedSource<ScalarFieldTag>> /*meta*/) const {

  It must support being called with a tmpl::list of all system-variable tags prefixed with Tags::FixedSource.

• They define a variables function that provides data for all background quantities, if any are listed in the background_fields of the system (see elliptic::protocols::FirstOrderSystem). The function must have this signature:

    template <typename... RequestedTags>
    tuples::TaggedTuple<RequestedTags...> variables(  // NOLINT
        const tnsr::I<DataVector, Dim>& x, const Mesh<Dim>& /*mesh*/,
        const InverseJacobian<DataVector, Dim, Frame::ElementLogical,
                              Frame::Inertial>&
        /*inv_jacobian*/,
        tmpl::list<RequestedTags...> /*meta*/) const {

  It must support being called with a tmpl::list of all background tags. It may use the mesh and inv_jacobian to compute numerical derivatives.

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The documentation for this class was generated from the following file:

• src/PointwiseFunctions/InitialDataUtilities/Background.hpp