ESPResSo
Extensible Simulation Package for Research on Soft Matter Systems
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PlaneWave.hpp
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1/*
2 * Copyright (C) 2010-2022 The ESPResSo project
3 *
4 * This file is part of ESPResSo.
5 *
6 * ESPResSo is free software: you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
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14 * GNU General Public License for more details.
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18 */
19#ifndef CORE_EXTERNAL_FIELD_FIELDS_PLAIN_WAVE_HPP
20#define CORE_EXTERNAL_FIELD_FIELDS_PLAIN_WAVE_HPP
21
22#include "jacobian_type.hpp"
23
24#include <utils/Vector.hpp>
26
27#include <cmath>
28#include <cstddef>
29
30namespace FieldCoupling {
31namespace Fields {
32/**
33 * @brief A plane wave.
34 *
35 * A time-dependent plane wave, with a certain (vector-valued)
36 * amplitude, wave vector frequency and phase.
37 *
38 * See https://en.wikipedia.org/wiki/Plane_wave
39 */
40template <typename T, std::size_t codim> class PlaneWave {
41public:
42 using value_type =
44 using jacobian_type = detail::jacobian_type<T, codim>;
45
46private:
47 value_type m_amplitude;
48 value_type m_k;
49 T m_omega;
50 T m_phase;
51
52public:
54 : m_amplitude(amplitude), m_k(k), m_omega(omega), m_phase(phase) {}
55
56 value_type &amplitude() { return m_amplitude; }
57 value_type &k() { return m_k; }
58 T &omega() { return m_omega; }
59 T &phase() { return m_phase; }
60
61 /**
62 * brief Evaluate field.
63 *
64 * @param x Where?
65 * @param t When?
66 * @return Value of the field at point x and time t.
67 */
68 value_type operator()(const Utils::Vector3d &x, T t = 0.) const {
69 return m_amplitude * sin(m_k * x - m_omega * t + m_phase);
70 }
71
72 /**
73 * brief Evaluate the Jacobian matrix of the field.
74 *
75 * See https://en.wikipedia.org/wiki/Jacobian_matrix_and_determinant
76 * In the special case of a scalar field, the Jacobian is the gradient of
77 * the field.
78 *
79 * @param x Where?
80 * @param t When?
81 * @return Jacobian matrix
82 */
83 jacobian_type jacobian(const Utils::Vector3d &x, T t = 0.) const {
85
86 return tensor_product(m_amplitude, m_k) *
87 cos(m_k * x - m_omega * t + m_phase);
88 }
89
90 bool fits_in_box(const Utils::Vector3d &) const { return true; }
91};
92} // namespace Fields
93} // namespace FieldCoupling
94
95#endif
Vector implementation and trait types for boost qvm interoperability.
value_type operator()(const Utils::Vector3d &x, T t=0.) const
brief Evaluate field.
Definition PlaneWave.hpp:68
typename Utils::decay_to_scalar< Utils::Vector< T, codim > >::type value_type
Definition PlaneWave.hpp:43
bool fits_in_box(const Utils::Vector3d &) const
Definition PlaneWave.hpp:90
PlaneWave(const value_type amplitude, const value_type &k, T omega, T phase)
Definition PlaneWave.hpp:53
jacobian_type jacobian(const Utils::Vector3d &x, T t=0.) const
brief Evaluate the Jacobian matrix of the field.
Definition PlaneWave.hpp:83
detail::jacobian_type< T, codim > jacobian_type
Definition PlaneWave.hpp:44
Matrix< T, N, M > tensor_product(const Vector< T, N > &x, const Vector< T, M > &y)
Meta function to turns a Vector<1, T> into T.
Definition Vector.hpp:478