Make buffer of scraped particles available to Python code (#2164)

* Added wrapper to get number of particle species tracked by the scraper

Not sure if this is going to be useful, but it demonstrates a method to get information
  from the ParticleBoundaryBuffer into Python.

* Stubbed out the main wrapper functions

* Added parameters to wrapper

* Added wrapper for getting the number of particles scraped of a species on a boundary

* added picmi arguments to scrape particles at the domain boundary

* Added wrapper to get the full particle buffer into python

* rearanged the getBuffer properties code a little

* Added docstrings +other suggested changes

* Added num_particles_impacted_boundary docstring

* fixed mistake in docstring

* Changed boundary parameter to be a string for clarity

* Fixed issue with the boundary parameter for scraping

* Fixed issue with the boundary input for scraping stats wrapper

* Added demonstration of particle scraping wrapper

* Added analysis.py file

* Fix typo in one of the dimension maps

Co-authored-by: Roelof Groenewald <40245517+roelof-groenewald@users.noreply.github.com>

* Added before esolve to warpx evolve

* added test for the scraped particle buffer wrappers

* Moved python PICMI particle boundary scrape test

* Renamed test file to the correct name

* Removed old test

* added special functionality to get the timestep at which particles were scraped

* removed debug print

* added python wrapper for the clearParticles() function of the scraper buffer

* added special wrapper function to get the timesteps at which the particles in the boundary buffer were scraped

* updated test to match the non-PICMI test for the particle scraper buffer

* Fix uncaught rebase mistake

* re-activated picmi test of accessing the scraped particle buffers via python

* added documentation for the new parameters involved in the scraped particle buffer and fixed remaining issue with picmi test

* changes requested during code review

Co-authored-by: mkieburtz <michaelkieburtz@gmail.com>
Co-authored-by: Roelof <roelof.groenewald@modernelectron.com>
Co-authored-by: Roelof Groenewald <40245517+roelof-groenewald@users.noreply.github.com>

1 files changed, 26 insertions, 1 deletions

diff --git a/Source/Particles/ParticleBoundaryBuffer.cpp b/Source/Particles/ParticleBoundaryBuffer.cpp
index f84d05b28..16465ac76 100644
--- a/Source/Particles/ParticleBoundaryBuffer.cpp
+++ b/Source/Particles/ParticleBoundaryBuffer.cpp
@@ -97,7 +97,7 @@ void ParticleBoundaryBuffer::printNumParticles () const {
                 int np = buffer[i].isDefined() ? buffer[i].TotalNumberOfParticles(false) : 0;
                 amrex::Print() << "Species " << getSpeciesNames()[i] << " has "
                                << np << " particles in the boundary buffer "
-                               << " for side " << iside << " of dim " << idim << "\n";
+                               << "for side " << iside << " of dim " << idim << "\n";
             }
         }
     }
@@ -232,3 +232,28 @@ void ParticleBoundaryBuffer::gatherParticles (MultiParticleContainer& mypc,
     amrex::ignore_unused(distance_to_eb, dxi);
 #endif
 }
+
+int ParticleBoundaryBuffer::getNumParticlesInContainer(
+        const std::string species_name, int boundary) {
+
+    auto& buffer = m_particle_containers[boundary];
+    auto index = WarpX::GetInstance().GetPartContainer().getSpeciesID(species_name);
+
+    if (buffer[index].isDefined()) return buffer[index].TotalNumberOfParticles(false);
+    else return 0;
+}
+
+ParticleBuffer::BufferType<amrex::PinnedArenaAllocator>&
+ParticleBoundaryBuffer::getParticleBuffer(const std::string species_name, int boundary) {
+
+    auto& buffer = m_particle_containers[boundary];
+    auto index = WarpX::GetInstance().GetPartContainer().getSpeciesID(species_name);
+
+    AMREX_ALWAYS_ASSERT_WITH_MESSAGE(m_do_boundary_buffer[boundary][index],
+                                     "Attempted to get particle buffer for boundary "
+                                     + boundary + ", which is not used!");
+    AMREX_ALWAYS_ASSERT_WITH_MESSAGE(buffer[index].isDefined(),
+                                     "Tried to get a buffer that is not defined!");
+
+    return buffer[index];
+}