Improve EMParticleContainer::InitParticles #166
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atmyers
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Nov 6, 2025
ExampleCodes/Particles/ElectromagneticPIC/Source/EMParticleContainerInit.cpp
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atmyers
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Nov 6, 2025
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The most significant change this PR makes is that it switches the order in which particles are initialized from
(uix * ny + uiy) * nz + uizto(uiz * ny + uiy) * nx + uix. The new way has uix as the fastest-moving dimension, which is significantly faster in particle-grid operations, especially if num_ppc is 1.The calculation of cellid is then further simplified by using Array4 and removing the index clamping, which is not necessary as the ParallelFor iterates over the same box.
Gpu::exclusive_scan is replaced by Scan::ExclusiveSum so that the return value can be used for num_to_add.
DefineAndReturnParticleTile is used to be more concise and make sure that the tile is defined.
ParticleTileData is used instead of realarray.