leonarski_f
b4b68d368f
RefineModel (Refinement.h) refines a placed model against the merge, reading and writing nothing: - placement stage (R1): every chain of 50+ atoms as a rigid body at once (L-BFGS on six parameters per chain, their gradient from the per-atom one through Ceres jets), then one B shift per residue; - restrained stage (R2): positions and isotropic B of every atom of a residue the embedded dictionary describes, the rest held fixed but kept in Fcalc and the mask; riding hydrogens added by gemmi's topology, moved with their parents, re-placed every macro-cycle. Macro-cycles refit the mask, the scale and bulk solvent (FitModelScale / ModelScaleGPUPool) and the likelihood's D and beta (ML on the free set in resolution bins), rebuild the repulsion pairs (symmetry mates included), then L-BFGS on positions and, where chosen, on B. - weights: a ladder of full refinements at multiples of the gradient-balanced X-ray weight, chosen by R-free within bond/angle bounds (ties to the tighter geometry), then the B refinement tried at its own weights and kept only where it beats B held by more than the tie. The target and its gradient (RefinementXray, RefinementGPU): the Rice/centric amplitude likelihood (RefinementMath.h, shared host/device code), the gradient by Agarwal's FFT method - the adjoint of the reciprocal-space symmetry composition into a half-l (CPU) or half-u (cuFFT) spectrum, one inverse real transform, then each atom's density derivatives (xyz and B) summed over its box. On the GPU everything per evaluation stays on the device: ModelDensityGPU's gather, r2c, a fused compose + likelihood kernel, a CSR gather for the adjoint (no atomics), c2r, one warp per atom for the gradient; the restraints are one kernel per restraint plus a per-atom gather of gradient slots; cub reductions. Deterministic. Restraints (RefinementRestraints): bonds, angles, torsions (with esd, no phi/psi, no alternative sugar puckers), chiral volumes, least-squares planes from gemmi's Topo; repulsions beyond 1-4 (vdW radii from the dictionary's energy library, 2.6 A for H-bond pairs, 1.9 A metal-N/O/S); B similarity of bonded and angle-related atoms. DensityBlobs (D1): gemmi's flood-fill blobs of mFo-DFc above 3 sigma peaking above 4 sigma, placed beside the model and labelled WATER / ION / LIGAND / MODEL_ERROR by distance, contacts, volume and the anomalous map. tools/rugnux_refine_test refines a model against a finished run's p.mtz (developer utility, not installed). Tests: likelihood derivative, the embedded library, restraint values on ideal residues and every restraint kind's gradient against finite differences (CPU, and the GPU against the CPU), the X-ray gradient against finite differences in P1, P212121, C2 and P6122 (CPU and GPU), and a synthetic refinement that recovers a shaken model. Credits in docs/ACKNOWLEDGEMENT.md and at the algorithms. Measured on the open arm's battery outputs against REFMAC 5.8, 10 cycles, same p.mtz, free set and start model (R-free): 5reo 0.2228 vs 0.2236, 8dyz 0.1733 vs 0.1651, 9chw 0.1995 vs 0.1969 (CPU engine). Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_015CeEGgpKdfkCTJb3YNMJcu (cherry picked from commit 8efe6f2322b3bfdae580bb34f256e67730dfc3c2)
25 lines
1.5 KiB
C++
25 lines
1.5 KiB
C++
// SPDX-FileCopyrightText: 2026 Filip Leonarski, Paul Scherrer Institute <filip.leonarski@psi.ch>
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// SPDX-License-Identifier: GPL-3.0-only
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#pragma once
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// Restrained refinement's targets on a GPU (CUDA builds only): the RefinementEngine of RefinementXray.h with
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// everything per evaluation on the device - the atoms' density (ModelDensityGPU's gather), its transform, the
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// symmetry composed in reciprocal space, the likelihood target, the derivative map by the inverse transform
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// of the target's derivatives and every atom's gradient read off it, and the geometry restraints. The host
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// passes positions in and gets one value and one gradient per atom back.
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#include <memory>
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#include "RefinementXray.h"
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// The engine for refining `model` against `refl` on `device`, or null where the GPU cannot take this case (an
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// atom's box wider than the cell, too many symmetry operators) or its memory is over `budget` bytes.
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// `b_max`: the largest B an atom may reach, which the gather's reserve is sized for. Throws JFJochException on a
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// CUDA failure.
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std::unique_ptr<RefinementEngine> MakeRefinementEngineGPU(int device, const gemmi::UnitCell &cell,
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const gemmi::SpaceGroup &sg, double d_min,
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const RefinementReflections &refl,
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const gemmi::Model &model, double b_max, size_t budget,
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size_t *device_bytes = nullptr);
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