eval_f and ftilda and rho now take vector of x and output vector on x

This commit is contained in:
Vasco C. B. Ferreira
2026-06-30 14:11:59 +02:00
parent b6c891bc70
commit be8cf7aa31
5 changed files with 132 additions and 57 deletions
-5
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@@ -3,8 +3,3 @@
This simulation of the Vlasov-Poisson system in 1x1v dimensions uses
- [NuFI algorithm](https://doi.org/10.1002/pamm.202300162)
- [deal.ii](https://dealii.org/) FEM package
---
Todo:
- fix eval and saving fields.
- something with periodicity or eval range in x
+14 -5
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@@ -4,8 +4,10 @@
#include "nufi/parameters.h"
#include "nufi/poisson_problem.h"
#include <cmath>
#include <cstddef>
#include <deal.II/base/function.h>
#include <deal.II/base/point.h>
#include <vector>
using namespace dealii;
@@ -69,15 +71,22 @@ inline double f0(const double x, const double v,
}
// wrapper for eval_point() { VectorTools::point_values() }
inline double eval(double x, const PoissonProblem<1> &poisson,
inline std::vector<double> eval(std::vector<double> &X,
const PoissonProblem<1> &poisson,
const Vector<double> &solution) noexcept {
size_t x_size = X.size();
std::vector<double> evals(x_size);
std::vector<Point<1>> Points(x_size);
x -= Parameters::X_DOMAIN_LEFT;
for (size_t i = 0; i < x_size; ++i) {
X[i] = X[i] - Parameters::X_DOMAIN_LEFT;
X[i] = X[i] - Parameters::LX * std::floor(X[i] * Parameters::LX_INV);
x = x - Parameters::LX * std::floor(x * Parameters::LX_INV); // in domain
Points[i][0] = X[i];
}
return eval_point_grad<1>(poisson.get_mapping(), poisson.get_dof_handler(),
solution, Point<1>(x));
return eval_vector_grad(poisson.get_mapping(), poisson.get_dof_handler(),
solution, Points);
}
inline double integral_space_vector(const PoissonProblem<1> &poisson,
+5 -3
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@@ -19,14 +19,16 @@ public:
NuFISolver();
void run();
double eval_rho(unsigned int n, const double x,
std::vector<double> eval_rho(unsigned int n, std::vector<double> &x,
const PoissonProblem<1> &poisson,
const std::vector<Vector<double>> &phi_history,
const unsigned int Nv = Parameters::NV) const;
double eval_ftilda(unsigned int n, double x, double u,
std::vector<double>
eval_ftilda(unsigned int, std::vector<double> &x, double u,
const PoissonProblem<1> &poisson,
const std::vector<Vector<double>> &phi_history) const;
double eval_f(unsigned int n, double x, double u,
std::vector<double>
eval_f(unsigned int n, std::vector<double> &x, double u,
const PoissonProblem<1> &poisson,
const std::vector<Vector<double>> &phi_history) const;
+14
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@@ -184,6 +184,20 @@ eval_point_grad(const Mapping<dim> &mapping, const DoFHandler<dim> &dof_handler,
return Ex;
}
template <int dim>
std::vector<double> eval_vector_grad(const Mapping<dim> &mapping,
const DoFHandler<dim> &dof_handler,
const Vector<double> &solution,
const std::vector<Point<dim>> &points) {
size_t p_size = points.size();
std::vector<double> Ex(p_size);
for (size_t i = 0; i < p_size; ++i)
Ex[i] = eval_point_grad(mapping, dof_handler, solution, points[i]);
return Ex;
}
template <int dim>
double eval_point_value(const Mapping<dim> &mapping,
const DoFHandler<dim> &dof_handler,
+88 -33
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@@ -22,72 +22,127 @@
using namespace dealii;
double
NuFISolver::eval_ftilda(unsigned int n, double x, double u,
std::vector<double>
NuFISolver::eval_ftilda(unsigned int n, std::vector<double> &X, double u,
const PoissonProblem<1> &poisson,
const std::vector<Vector<double>> &phi_history) const {
if (n == 0)
return f0(x, u);
double Ex;
size_t x_size = X.size();
std::vector<double> U(x_size, u);
std::vector<double> results(x_size);
if (n == 0) {
for (size_t i = 0; i < x_size; ++i)
results[i] = f0(X[i], U[i]);
return results;
}
std::vector<double> Ex(x_size);
std::vector<double> tmp(x_size);
// We omit the initial half-step.
while (--n) {
x = x - Parameters::DT * u;
Ex = -eval(x, poisson, phi_history[n]);
u = u + Parameters::DT * Ex;
for (size_t i = 0; i < x_size; ++i)
X[i] = X[i] - Parameters::DT * U[i];
tmp = eval(X, poisson, phi_history[n]); // call eval only once
for (size_t i = 0; i < x_size; ++i) {
Ex[i] = -tmp[i];
U[i] = U[i] + Parameters::DT * Ex[i];
}
}
// The final half-step.
x = x - Parameters::DT * u;
Ex = -eval(x, poisson, phi_history[n]);
u += 0.5 * Parameters::DT * Ex;
for (size_t i = 0; i < x_size; ++i)
X[i] = X[i] - Parameters::DT * U[i];
return f0(x, u);
tmp = eval(X, poisson, phi_history[n]); // call eval only once
for (size_t i = 0; i < x_size; ++i) {
Ex[i] = -tmp[i];
U[i] = U[i] + 0.5 * Parameters::DT * Ex[i];
}
for (size_t i = 0; i < x_size; ++i)
results[i] = f0(X[i], U[i]);
return results;
}
double
NuFISolver::eval_f(unsigned int n, double x, double u,
std::vector<double>
NuFISolver::eval_f(unsigned int n, std::vector<double> &X, double u,
const PoissonProblem<1> &poisson,
const std::vector<Vector<double>> &phi_history) const {
if (n == 0)
return f0(x, u);
double Ex;
size_t x_size = X.size();
std::vector<double> U(x_size, u);
std::vector<double> results(x_size);
if (n == 0) {
for (size_t i = 0; i < x_size; ++i)
results[i] = f0(X[i], U[i]);
return results;
}
std::vector<double> Ex(x_size);
std::vector<double> tmp(x_size);
// Initial half-step.
Ex = -eval(x, poisson, phi_history[n]);
u += 0.5 * Parameters::DT * Ex;
tmp = eval(X, poisson, phi_history[n]); // call eval only once
for (size_t i = 0; i < x_size; ++i) {
Ex[i] = -tmp[i];
U[i] = U[i] + 0.5 * Parameters::DT * Ex[i];
}
while (--n) {
x = x - Parameters::DT * u;
Ex = -eval(x, poisson, phi_history[n]);
u = u + Parameters::DT * Ex;
for (size_t i = 0; i < x_size; ++i)
X[i] = X[i] - Parameters::DT * U[i];
tmp = eval(X, poisson, phi_history[n]); // call eval only once
for (size_t i = 0; i < x_size; ++i) {
Ex[i] = -tmp[i];
U[i] = U[i] + Parameters::DT * Ex[i];
}
}
// The final half-step.
x = x - Parameters::DT * u;
Ex = -eval(x, poisson, phi_history[n]);
u += 0.5 * Parameters::DT * Ex;
for (size_t i = 0; i < x_size; ++i)
X[i] = X[i] - Parameters::DT * U[i];
return f0(x, u);
tmp = eval(X, poisson, phi_history[n]); // call eval only once
for (size_t i = 0; i < x_size; ++i) {
Ex[i] = -tmp[i];
U[i] = U[i] + 0.5 * Parameters::DT * Ex[i];
}
double NuFISolver::eval_rho(unsigned int n, const double x,
for (size_t i = 0; i < x_size; ++i)
results[i] = f0(X[i], U[i]);
return results;
}
std::vector<double>
NuFISolver::eval_rho(unsigned int n, std::vector<double> &X,
const PoissonProblem<1> &poisson,
const std::vector<Vector<double>> &phi_history,
const unsigned int Nv) const {
size_t x_size = X.size();
const double dv =
(Parameters::V_DOMAIN_RIGHT - Parameters::V_DOMAIN_LEFT) / Nv;
const double v_min = Parameters::V_DOMAIN_LEFT + 0.5 * dv;
double integral = 0.0;
std::vector<double> integral(x_size, 0.0);
#pragma omp parallel for reduction(+ : integral)
for (unsigned int i = 0; i < Nv; ++i)
integral += eval_ftilda(n, x, v_min + i * dv, poisson, phi_history);
return 1.0 - integral * dv;
std::vector<double> tmp_int(x_size);
for (unsigned int i = 0; i < Nv; ++i) {
tmp_int = eval_ftilda(n, X, v_min + i * dv, poisson,
phi_history); // used eval_ftilda once per i
for (size_t ii = 0; ii < x_size; ++ii)
integral[ii] += tmp_int[ii];
}
for (size_t i = 0; i < x_size; ++i)
integral[i] = 1 - integral[i] * dv;
return integral;
}
void NuFISolver::run() {