1 files changed, 52 insertions, 0 deletions
diff --git a/Source/FieldSolver/SpectralSolver/SpectralKSpaceRZ.cpp b/Source/FieldSolver/SpectralSolver/SpectralKSpaceRZ.cpp
new file mode 100644
index 000000000..133b2ef65
--- /dev/null
+++ b/Source/FieldSolver/SpectralSolver/SpectralKSpaceRZ.cpp
@@ -0,0 +1,52 @@
+/* Copyright 2019 David Grote
+ *
+ * This file is part of WarpX.
+ *
+ * License: BSD-3-Clause-LBNL
+ */
+#include "Utils/WarpXConst.H"
+#include "SpectralKSpaceRZ.H"
+
+#include <cmath>
+
+/* \brief Initialize k space object.
+ *
+ * \param realspace_ba Box array that corresponds to the decomposition
+ * of the fields in real space (cell-centered ; includes guard cells)
+ * \param dm Indicates which MPI proc owns which box, in realspace_ba.
+ * \param realspace_dx Cell size of the grid in real space
+ */
+SpectralKSpaceRZ::SpectralKSpaceRZ (const amrex::BoxArray& realspace_ba,
+                                    const amrex::DistributionMapping& dm,
+                                    const amrex::RealVect realspace_dx)
+{
+    dx = realspace_dx;  // Store the cell size as member `dx`
+
+    AMREX_ALWAYS_ASSERT_WITH_MESSAGE(
+        realspace_ba.ixType() == amrex::IndexType::TheCellType(),
+        "SpectralKSpaceRZ expects a cell-centered box.");
+
+    // Create the box array that corresponds to spectral space
+    amrex::BoxList spectral_bl; // Create empty box list
+
+    // Loop over boxes and fill the box list
+    for (int i=0; i < realspace_ba.size(); i++ ) {
+        // For local FFTs, boxes in spectral space start at 0 in
+        // each direction and have the same number of points as the
+        // (cell-centered) real space box
+        amrex::Box realspace_bx = realspace_ba[i];
+        amrex::IntVect fft_size = realspace_bx.length();
+        amrex::IntVect spectral_bx_size = fft_size;
+        // Define the corresponding box
+        amrex::Box spectral_bx = amrex::Box(amrex::IntVect::TheZeroVector(),
+                              spectral_bx_size - amrex::IntVect::TheUnitVector() );
+        spectral_bl.push_back(spectral_bx);
+    }
+    spectralspace_ba.define(spectral_bl);
+
+    // Allocate the components of the kz vector
+    const int i_dim = 1;
+    const bool only_positive_k = false;
+    k_vec[i_dim] = getKComponent(dm, realspace_ba, i_dim, only_positive_k);
+
+}