SpECTRE  v2024.05.11
control_system::ControlErrors::Translation Struct Reference

Control error in the 3D Translation coordinate map. More...

#include <Translation.hpp>

Public Types

using object_centers = domain::object_list< domain::ObjectLabel::A, domain::ObjectLabel::B >
using options = tmpl::list<>

Public Member Functions

void pup (PUP::er &)
template<typename Metavariables , typename... TupleTags>
DataVector operator() (const ::TimescaleTuner< true > &, const Parallel::GlobalCache< Metavariables > &cache, const double time, const std::string &, const tuples::TaggedTuple< TupleTags... > &measurements)

Static Public Attributes

static constexpr size_t expected_number_of_excisions = 2
static constexpr Options::String help

Detailed Description

Control error in the 3D Translation coordinate map.


Computes the error in how much the system has translated by using a modified version of Eq. (42) from [140]. The equation is

\[ \left(0, \delta\vec{T}\right) = a\mathbf{q}\left(\frac{1}{2}(\mathbf{x}_A + \mathbf{x}_B - \frac{1}{2}(\mathbf{c}_A + \mathbf{c}_B)) - \mathbf{\delta q}\wedge\frac{1}{2}(\mathbf{c}_A + \mathbf{c}_B) - \frac{\delta a}{a}\frac{1}{2}(\mathbf{c}_A + \mathbf{c}_B) \right)\mathbf{q}^* \]

where object A is located on the positive x-axis in the grid frame, bold face letters are quaternions, vectors are promoted to quaternions as \( \mathbf{v} = (0, \vec{v}) \), \( \mathbf{q} \) is the quaternion from the Rotation map, \( a \) is the function \( a(t) \) from the CubicScale map, \( \mathbf{\delta q}\wedge\mathbf{c}_A \equiv (0, \delta\vec{q} \times \vec{c}_A) \), \( \delta\vec{q} \) is the Rotation control error, and \( \delta a\) is the Expansion control error.


  • This control error requires that there be exactly two objects in the simulation
  • Currently both these objects must be black holes
  • Currently this control error can only be used with the Translation control system
  • There must exist an expansion map and a quaternion rotation map in the coordinate map with names "Expansion" and "Rotation", respectively.

Member Data Documentation

◆ help

constexpr Options::String control_system::ControlErrors::Translation::help
Initial value:
"Computes the control error for translation control. This should not "
"take any options."}

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