DoFSet.cc

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#include <casm/crystallography/DoFSet.hh>
#include <casm/crystallography/SymType.hh>
#include <unordered_set>
#include <vector>
 
#include "casm/crystallography/Site.hh"
 
namespace CASM {
namespace xtal {
std::vector<std::string> component_descriptions(DoFSet const &dofset) {
  if (dofset.basis().isIdentity(TOL) &&
      dofset.basis().rows() == dofset.basis().cols())
    return dofset.traits().variable_descriptions();
  else
    return dofset.component_names();
}
 
bool DoFSetIsEquivalent_f::_traits_match(const DoFSet &other_value) const {
  return m_reference_dofset.traits().name() == other_value.traits().name();
}
 
bool DoFSetIsEquivalent_f::_basis_spans_same_space(
    const DoFSet &other_value) const {
  const auto &reference_basis = m_reference_dofset.basis();
  const auto &other_basis = other_value.basis();
 
  if (reference_basis.cols() != other_basis.cols()) return false;
 
  // If not a square matrix, make sure that column-space _after_basis is
  // identical to that of _before_basis
  if (reference_basis.cols() < other_basis.rows()) {
    // Find rank of augmented matrix. If it is the same as rank of DoF Basis,
    // then the two matrices are similar (and, thus, equivalent)
    Eigen::MatrixXd aug(reference_basis.rows(), 2 * reference_basis.cols());
    aug << reference_basis, other_basis;
 
    Eigen::ColPivHouseholderQR<Eigen::MatrixXd> qr(aug);
    qr.setThreshold(m_tol);
    if (qr.rank() != m_reference_dofset.dim()) return false;
  }
 
  return true;
}
 
bool DoFSetIsEquivalent_f::operator()(const DoFSet &other_value) const {
  return this->_traits_match(other_value) &&
         this->_basis_spans_same_space(other_value);
}
 
Eigen::MatrixXd dofset_transformation_matrix(const Eigen::MatrixXd &from_basis,
                                             const Eigen::MatrixXd &to_basis,
                                             double tol) {
  Eigen::MatrixXd U = from_basis.colPivHouseholderQr().solve(to_basis);
  if (!(U.transpose() * U).eval().isIdentity(tol)) {
    throw std::runtime_error("Cannot find orthogonal symmetry representation!");
  }
  return U;
}
}  // namespace xtal
}  // namespace CASM
 
namespace CASM {
namespace sym {
xtal::DoFSet copy_apply(const xtal::SymOp &op, const xtal::DoFSet &dof) {
  Eigen::MatrixXd transformation_matrix = dof.traits().symop_to_matrix(
      get_matrix(op), get_translation(op), get_time_reversal(op));
  return xtal::DoFSet(dof.traits(), dof.component_names(),
                      transformation_matrix * dof.basis());
}
}  // namespace sym
 
}  // namespace CASM