Sampling volume

amr-wind/utilities/sampling/CMakeLists.txt

@@ -12,5 +12,6 @@ target_sources(${amr_wind_lib_name}
   KineticEnergy.cpp
   Enstrophy.cpp
   FreeSurface.cpp
+  VolumeSampler.cpp
   WaveEnergy.cpp
   )

amr-wind/utilities/sampling/VolumeSampler.H

@@ -0,0 +1,63 @@
+#ifndef VOLUMESAMPLER_H
+#define VOLUMESAMPLER_H
+
+#include "amr-wind/utilities/sampling/SamplerBase.H"
+
+namespace amr_wind::sampling {
+
+/** Sample data on uniform grids
+ *  \ingroup sampling
+ *
+ *  Defines probe locations on a volume defined by an
+ *  `axis` that originates from the point `origin`.
+ *  The resolution of the volume is defined by the vector npts_dir.
+ *
+ */
+class VolumeSampler : public SamplerBase::Register<VolumeSampler>
+{
+public:
+    static std::string identifier() { return "VolumeSampler"; }
+
+    explicit VolumeSampler(const CFDSim& /*unused*/);
+
+    ~VolumeSampler() override;
+
+    /** Read user inputs and initialize the sampling object
+     *
+     *  \param key Prefix used to parse inputs from file
+     */
+    void initialize(const std::string& key) override;
+
+    //! Populate and return a vector of probe locations to be sampled
+    void sampling_locations(SampleLocType& /*locs*/) const override;
+
+    void
+    define_netcdf_metadata(const ncutils::NCGroup& /*unused*/) const override;
+    void
+    populate_netcdf_metadata(const ncutils::NCGroup& /*unused*/) const override;
+
+    //! Name of this sampling object
+    std::string label() const override { return m_label; }
+    std::string& label() override { return m_label; }
+
+    //! Unique identifier for this set of probe locations
+    int id() const override { return m_id; }
+    int& id() override { return m_id; }
+
+    //! Number of probe locations along the line
+    int num_points() const override { return m_npts; }
+
+private:
+    amrex::Vector<amrex::Real> m_axis;
+    amrex::Vector<amrex::Real> m_origin;
+    amrex::Vector<int> m_npts_dir;
+
+    std::string m_label;
+
+    int m_id{-1};
+    int m_npts{0};
+};
+
+} // namespace amr_wind::sampling
+
+#endif /* VOLUMESAMPLER_H */

amr-wind/utilities/sampling/VolumeSampler.cpp

@@ -0,0 +1,79 @@
+#include <limits>
+
+#include "amr-wind/utilities/sampling/VolumeSampler.H"
+
+#include "AMReX_ParmParse.H"
+
+namespace amr_wind::sampling {
+
+VolumeSampler::VolumeSampler(const CFDSim& /*unused*/) {}
+
+VolumeSampler::~VolumeSampler() = default;
+
+void VolumeSampler::initialize(const std::string& key)
+{
+    amrex::ParmParse pp(key);
+
+    pp.getarr("axis", m_axis);
+    pp.getarr("origin", m_origin);
+    pp.getarr("num_points", m_npts_dir);
+    AMREX_ALWAYS_ASSERT(static_cast<int>(m_axis.size()) == AMREX_SPACEDIM);
+    AMREX_ALWAYS_ASSERT(static_cast<int>(m_origin.size()) == AMREX_SPACEDIM);
+    AMREX_ALWAYS_ASSERT(static_cast<int>(m_npts_dir.size()) == AMREX_SPACEDIM);
+
+    // Update total number of points
+    const size_t tmp = m_npts_dir[0] * m_npts_dir[1] * m_npts_dir[2];
+    if (tmp > static_cast<size_t>(std::numeric_limits<int>::max())) {
+        amrex::Abort(
+            "VolumeSampler: Plane definition " + key +
+            " exceeds 32-bit integer limits");
+    }
+    m_npts = static_cast<int>(tmp);
+}
+
+void VolumeSampler::sampling_locations(SampleLocType& locs) const
+{
+    locs.resize(m_npts);
+
+    amrex::Array<amrex::Real, AMREX_SPACEDIM> dx;
+
+    for (int d = 0; d < AMREX_SPACEDIM; ++d) {
+        dx[d] = m_axis[d] / m_npts_dir[d];
+    }
+
+    int idx = 0;
+    for (int k = 0; k < m_npts_dir[2]; ++k) {
+        for (int j = 0; j < m_npts_dir[1]; ++j) {
+            for (int i = 0; i < m_npts_dir[0]; ++i) {
+                for (int d = 0; d < AMREX_SPACEDIM; ++d) {
+                    locs[idx][0] = m_origin[0] + dx[0] * i;
+                    locs[idx][1] = m_origin[1] + dx[1] * j;
+                    locs[idx][2] = m_origin[2] + dx[2] * k;
+                }
+                ++idx;
+            }
+        }
+    }
+}
+
+#ifdef AMR_WIND_USE_NETCDF
+void VolumeSampler::define_netcdf_metadata(const ncutils::NCGroup& grp) const
+{
+    const std::vector<int> ijk{m_npts_dir[0], m_npts_dir[1], m_npts_dir[2]};
+    grp.put_attr("sampling_type", identifier());
+    grp.put_attr("ijk_dims", ijk);
+    grp.put_attr("origin", m_origin);
+    grp.put_attr("axis", m_axis);
+}
+
+void VolumeSampler::populate_netcdf_metadata(const ncutils::NCGroup&) const {}
+#else
+void VolumeSampler::define_netcdf_metadata(
+    const ncutils::NCGroup& /*unused*/) const
+{}
+void VolumeSampler::populate_netcdf_metadata(
+    const ncutils::NCGroup& /*unused*/) const
+{}
+#endif
+
+} // namespace amr_wind::sampling

docs/sphinx/user/inputs_Sampling.rst

@@ -139,4 +139,16 @@ Example::
 The first line of the file contains the total number of probes for this set.
 This is followed by the coordinates (three real numbers), one line per probe.
 
+Sampling on a volume
+`````````````````````
 
+The ``VolumeSampler`` samples a 3D volume that starts at ``origin`` and
+extends to ``axis``. The resolution in all directions is specified by
+``num_points``.
+
+Example::
+
+  sampling.volume1.type        = VolumeSampler
+  sampling.volume1.axis        = 3.0 1.0 0.5
+  sampling.volume1.origin      = 0.0 0.0 -0.5
+  sampling.volume1.num_points  = 30 10 10