reorganized files

fields.hpp

@@ -0,0 +1,61 @@
+#ifndef FIELDS_HPP
+#define FIELDS_HPP
+
+#include <cmath>
+#include <deal.II/base/function.h>
+#include "parameters.hpp"
+
+using namespace dealii;
+
+inline double f0(const double x,
+                 const double v,
+                 const double eps = Parameters::EPS,
+                 const double k   = Parameters::WAVE_NR)
+{
+  const double prefactor = (1.0 + eps * std::cos(k*x));
+  const double gaussian  =
+      (v*v / std::sqrt(2.0 * M_PI)) *
+      std::exp(-0.5 * v*v);
+
+  return prefactor * gaussian;
+}
+
+inline double compute_rho(const double x,
+                          const unsigned int Nv = Parameters::NV)
+{
+  const double dv = (Parameters::V_DOMAIN_RIGHT - Parameters::V_DOMAIN_LEFT) / Nv;
+
+  double integral = 0.0;
+
+  for (unsigned int i = 0; i < Nv; ++i)
+  {
+    const double v = Parameters::V_DOMAIN_LEFT + (i + 0.5) * dv;
+    integral += f0(x, v) * dv;
+  }
+
+  return 1.0 - integral;
+}
+
+template <int dim>
+class ChargeDensity : public Function<dim>
+{
+public:
+  ChargeDensity(double eps,
+                double k,
+                unsigned int Nv)
+    : Function<dim>(1), eps(eps), k(k), Nv(Nv) {}
+
+  virtual double value(const Point<dim> &p,
+                       [[maybe_unused]] const unsigned int component = 0) const override
+  {
+    return compute_rho(p[0], Nv);
+  }
+
+private:
+  const double eps;
+  const double k;
+  const unsigned int Nv;
+};
+
+
+#endif