RustBCA v3.0.0

[drobnyjt]

RustBCA 3.0.0

The breaking changes are a new, seeded PRNG and deprecation of HDF5. With version 3.0.0, RustBCA should be faster, more numerically robust, and better tested.

Correctness

• Fixed Biersack-Varelas stopping power for ck!=1.0; split electronic stopping powers into their own functions and implemented testing of electronic stopping functions.
• Added additional assertions on Ed, Eb values (must be >0)
• Implemented recoil generation and particle advance routines using Duff et al.'s orthonormal basis instead of ad hoc switching between two cartesian bases - this should significantly increase the robustness and decrease the errors (when ux ~ 1) involved in the calculation of recoil locations and particle deflection. Additionally, this is slightly faster, as it requires fewer floating point operations.

Optimizations

• Implemented LazyLock initialized Lookup Tables (LUTs) for functions of (Za, Zb); this offers speedups of up to ~30%, with some new constraints: Za, Zb must be integers, and Z_MAX is currently hardcoded at 120.
• Changed all unnecessary invocations of powf to powi, sqrt, or cbrt. This change offered a ~5% speedup.
• Removed some redundant function calls - ~5% speedup.

New features

• New seeded PRNG; I've implemented a streaming PRNG, ChaCha8, that the user can seed manually. This makes RustBCA deterministic for all functions except some C/Fortran API functions where implementing it would be troublesome to the function calling.
• New INTERPOLATEDPLUS electronic stopping mode - this mode allows mild adjustments of the Bragg peak magnitude with a new parameter, c_i, in BiersackVarelas stopping, S_BV = ((S_LS)^(-ci) + (S_BB)^(-ci))^(-1/ci).
• added generalized RustBCA function wrappers; these allow one to call a complete RustBCA simulation from an input file dictionary, with the option to directly output lists of particles to memory or to print files as in the standalone code.

Other changes

• deprecated HDF5 input
• minor code cleanup/optimizations throughout
• added many more integration tests, tightened epsilon on some pre-existing unit tests

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This discussion was created from the release RustBCA v3.0.0.