1 files changed, 49 insertions, 0 deletions
diff --git a/Source/Initialization/CustomDensityProb.H b/Source/Initialization/CustomDensityProb.H
new file mode 100644
index 000000000..b00830e6c
--- /dev/null
+++ b/Source/Initialization/CustomDensityProb.H
@@ -0,0 +1,49 @@
+#ifndef CUSTOM_DENSITY_PROB_H_
+#define CUSTOM_DENSITY_PROB_H_
+
+#include <AMReX_ParmParse.H>
+#include <AMReX_Arena.H>
+#include <AMReX_Gpu.H>
+#include <AMReX_Dim3.H>
+
+// An example of Custom Density Profile
+
+// struct whose getDensity returns density at a given position computed from
+// a custom function, with runtime input parameters.
+struct InjectorDensityCustom
+{
+    InjectorDensityCustom (std::string const& species_name)
+        : p(nullptr)
+    {
+        // Read parameters for custom density profile from file, and
+        // store them in managed memory.
+        amrex::ParmParse pp(species_name);
+        std::vector<amrex::Real> v;
+        pp.getarr("custom_profile_params", v);
+        p = static_cast<amrex::Real*>
+            (amrex::The_Managed_Arena()->alloc(sizeof(amrex::Real)*v.size()));
+        for (int i = 0; i < static_cast<int>(v.size()); ++i) {
+            p[i] = v[i];
+        }
+    }
+
+    // Return density at given position, using user-defined parameters 
+    // stored in p.
+    AMREX_GPU_HOST_DEVICE
+    amrex::Real
+    getDensity (amrex::Real, amrex::Real, amrex::Real) const noexcept
+    {
+        return p[0];
+    }
+
+    // Note that we are not allowed to have non-trivial destructor.
+    // So we rely on clear() to free memory.
+    void clear () {
+        amrex::The_Managed_Arena()->free(p);
+    }
+
+private:
+    amrex::Real* p;
+};
+
+#endif