The fit has ONE parameter, and it was handed to Ceres as one residual block per rocking event - 8 million of them on a large crystal. Each block is a functor, an auto-diff cost function and a loss object on the heap, and the solver then factorises an 8-million-by-one Jacobian on every iteration. It cost 13.7 s. The residual is closed-form in k. A rotation preserves length, so |p_lab| is |e_mid| whatever k is and only the z component moves; Rodrigues gives it exactly: r(k) = C + A cos(a k) - B sin(a k) = C + R cos(a k + psi) C = lambda |e|^2 / 2 + u_z (u.e), A = e_z - u_z (u.e), B = (u x e)_z with a the event's angle from the sweep centre. That is the same function the functor computes - Ceres uses the exact Rodrigues form here, so there is no small-angle branch to disagree with - and it reduces the fit to minimising a smooth function of one variable over the interval the solver was bounded to. It is scanned on a grid and then closed in by golden section; the objective's curvature jumps wherever an event crosses the Huber knee, which is why this is not a Newton iteration. The coefficients are computed in double and stored narrowed. Their rounding moves the minimiser by ~1e-10, and k is carried downstream as a float, so the committed value is the same to far more digits than anything reads. One pass over the events yields the five per-fifth partial sums, so the all-data fit and the five leave-a-fifth-out folds share it. That matters because the jackknife only runs when the fit is big enough to act on, and on a crystal that trips it the old code paid for six full solves. The partials gather ahead of it counted first and then filled instead of growing one vector by push_back tens of millions of times, which copied the whole thing on every doubling. Measured: unchanged verdict and k to five decimals on the regression crystals. Full 24-crystal battery: same space group on all 24, none failed, 15m32s -> 13m35s together with the scale/merge changes. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
579 lines
36 KiB
C++
579 lines
36 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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#include "../../common/ParallelFor.h"
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#include "PostRefine.h"
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#include <algorithm>
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#include <array>
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#include <cmath>
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#include <mutex>
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#include "../../common/JFJochMath.h" // PI
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#include "XtalResidual.h" // XtalResidual (the positional detector<->reciprocal residual, step B)
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#include "LatticeReduction.h"
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#include "ceres/ceres.h"
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#include "ceres/rotation.h"
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namespace {
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// One integrated partial, flattened across all images.
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struct Partial {
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int h, k, l;
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float img;
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double I, sigma;
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double angle_rad; // frame mid-exposure goniometer angle
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double obs_x, obs_y; // observed spot centroid (pixels); NAN if the box sum found no centroid
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};
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// A rocking event and its precomputed reference reciprocal vector (phi=0 frame, from the indexed lattice).
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struct Event {
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double phi_obs; // rad, intensity-weighted rocking centroid
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double weight; // sqrt(sum I / sum sigma)
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double e_ref[3]; // h*a* + k*b* + l*c* at the reference (unrefined) cell/orientation
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int h, k, l;
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};
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// Distance-INDEPENDENT Ewald excitation residual for a uniform cell-scale parameter s and a refined
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// goniometer axis (3-vector). The header-distance miscalibration leaves a uniform cell scale; the axis is
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// the other phi_obs lever. Both are phi_obs-constrained (distance-independent). e_ref is the reference
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// reciprocal (h*a* + k*b* + l*c* at the indexed cell). On the Ewald sphere <=> |p|^2 + 2 p_z/lambda == 0.
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struct ScaleAxisExcitationResidual {
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ScaleAxisExcitationResidual(double lambda, double angle_rad, double weight, const double e_ref[3])
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: inv_lambda(1.0 / lambda), angle_rad(angle_rad), weight(weight),
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ex(e_ref[0]), ey(e_ref[1]), ez(e_ref[2]) {}
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template<typename T>
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bool operator()(const T *const s, const T *const axis, T *residual) const {
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const T inv_s = T(1) / s[0];
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const T p_ref[3] = {T(ex) * inv_s, T(ey) * inv_s, T(ez) * inv_s};
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const T aa[3] = {T(-angle_rad) * axis[0], T(-angle_rad) * axis[1], T(-angle_rad) * axis[2]};
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T p_lab[3];
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ceres::AngleAxisRotatePoint(aa, p_ref, p_lab);
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const T zeta = p_lab[0] * p_lab[0] + p_lab[1] * p_lab[1] + p_lab[2] * p_lab[2]
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+ T(2.0) * p_lab[2] * T(inv_lambda);
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residual[0] = T(weight) * zeta * T(0.5) / T(inv_lambda);
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return true;
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}
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const double inv_lambda, angle_rad, weight, ex, ey, ez;
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};
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// GONIOMETER ROTATION SCALE k: the same Ewald excitation residual, but with the cell scale and the axis
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// DIRECTION already committed by step A, so the single free quantity is how far the stage actually turned
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// per unit of commanded angle. Two differences from step A matter:
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// * the angle is measured from the CENTRE of the sweep, not from the goniometer's zero. The reference
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// orientation is the one rotation indexing fitted against the commanded angles, so it has already
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// absorbed the MEAN angle error; only the part that varies across the sweep is left to fit. Scaling the
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// absolute angle instead - which is what reading k off the length of step A's axis vector does - asks
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// the fit to also produce a constant offset it has no parameter for, and the least-squares compromise
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// shrinks k towards 1 by var(phi) / (var(phi) + phi_centre^2): exactly a factor of four for the common
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// case of a sweep starting at zero.
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// * e_mid is the reference reciprocal vector already turned to the sweep centre and divided by the
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// committed cell scale, so nothing but k is free.
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struct RotationScaleResidual {
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RotationScaleResidual(double lambda, double dangle_rad, const double u[3], const double e_mid[3])
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: inv_lambda(1.0 / lambda), dangle_rad(dangle_rad),
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ux(u[0]), uy(u[1]), uz(u[2]), ex(e_mid[0]), ey(e_mid[1]), ez(e_mid[2]) {}
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template<typename T>
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bool operator()(const T *const k, T *residual) const {
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const T a = T(-dangle_rad) * k[0];
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const T aa[3] = {a * T(ux), a * T(uy), a * T(uz)};
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const T p_ref[3] = {T(ex), T(ey), T(ez)};
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T p_lab[3];
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ceres::AngleAxisRotatePoint(aa, p_ref, p_lab);
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const T zeta = p_lab[0] * p_lab[0] + p_lab[1] * p_lab[1] + p_lab[2] * p_lab[2]
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+ T(2.0) * p_lab[2] * T(inv_lambda);
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residual[0] = zeta * T(0.5) / T(inv_lambda);
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return true;
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}
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const double inv_lambda, dangle_rad, ux, uy, uz, ex, ey, ez;
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};
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} // namespace
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PostRefineResult PostRefineRotationGeometry(const std::vector<IntegrationOutcome> &outcomes,
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const GoniometerAxis &axis,
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const DiffractionGeometry &nominal_geom,
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const CrystalLattice &reference_latt,
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const PostRefineSettings &settings,
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Logger &logger) {
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PostRefineResult result;
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result.geom = nominal_geom;
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result.cell = reference_latt.GetUnitCell();
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result.distance_before_mm = nominal_geom.GetDetectorDistance_mm();
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result.distance_after_mm = nominal_geom.GetDetectorDistance_mm();
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try {
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const double wedge_half = axis.GetWedge_deg() / 2.0;
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const double lambda = nominal_geom.GetWavelength_A();
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const Coord ax = axis.GetAxis();
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const Coord Astar = reference_latt.Astar(), Bstar = reference_latt.Bstar(), Cstar = reference_latt.Cstar();
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// Count first, then fill. Growing one vector by push_back over tens of millions of
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// reflections copies the whole thing every time it doubles - several gigabytes of pure
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// copying - and the counts are cheap to take. Each outcome then owns a slice, so the fill
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// runs on all threads and lands in the order the serial loop produced.
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const size_t nthreads = std::max(1, settings.num_threads);
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const int n_out = static_cast<int>(outcomes.size());
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std::vector<size_t> pts_offset(n_out + 1, 0);
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ParallelChunks(n_out, nthreads, [&](int lo, int hi) {
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for (int o = lo; o < hi; o++) {
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size_t keep = 0;
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for (const auto &r : outcomes[o].reflections)
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if (std::isfinite(r.I) && std::isfinite(r.sigma) && r.sigma > 0.0f)
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keep++;
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pts_offset[o + 1] = keep;
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}
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});
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for (int o = 0; o < n_out; o++)
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pts_offset[o + 1] += pts_offset[o];
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std::vector<Partial> pts(pts_offset[n_out]);
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ParallelChunks(n_out, nthreads, [&](int lo, int hi) {
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for (int o = lo; o < hi; o++) {
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size_t at = pts_offset[o];
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for (const auto &r : outcomes[o].reflections) {
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if (!std::isfinite(r.I) || !std::isfinite(r.sigma) || r.sigma <= 0.0f) continue;
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const double mid_deg = axis.GetAngle_deg(r.image_number) + wedge_half;
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const double ox = std::isfinite(r.observed_x) ? r.observed_x : NAN;
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const double oy = std::isfinite(r.observed_y) ? r.observed_y : NAN;
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pts[at++] = Partial{r.h, r.k, r.l, r.image_number, r.I, r.sigma,
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mid_deg * PI / 180.0, ox, oy};
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}
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}
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});
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logger.Info("Post-refine: {} partials gathered", pts.size());
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if (pts.size() < static_cast<size_t>(settings.min_events)) return result;
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std::sort(pts.begin(), pts.end(), [](const Partial &a, const Partial &b) {
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if (a.h != b.h) return a.h < b.h;
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if (a.k != b.k) return a.k < b.k;
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if (a.l != b.l) return a.l < b.l;
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return a.img < b.img;
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});
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// Split into rocking events (same raw hkl, adjacent frames). Only >=2-frame events carry an
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// unbiased phi_obs (a single-frame centroid is just the frame centre); precompute e_ref per event.
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constexpr float MAX_FRAME_GAP = 2.0f;
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std::vector<Event> events;
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size_t i = 0, event_frames = 0;
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while (i < pts.size()) {
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size_t j = i + 1;
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while (j < pts.size() && pts[j].h == pts[i].h && pts[j].k == pts[i].k && pts[j].l == pts[i].l
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&& pts[j].img - pts[j - 1].img <= MAX_FRAME_GAP)
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++j;
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if (j - i >= 2) {
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double sumI = 0, sumIphi = 0, sumSig = 0;
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for (size_t m = i; m < j; ++m) {
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const double Ipos = std::max(0.0, pts[m].I);
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sumI += Ipos; sumIphi += Ipos * pts[m].angle_rad; sumSig += pts[m].sigma;
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}
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if (sumI > 0.0 && sumSig > 0.0) {
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const double phi = sumIphi / sumI;
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event_frames += j - i;
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const Coord e = Astar * static_cast<float>(pts[i].h) + Bstar * static_cast<float>(pts[i].k)
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+ Cstar * static_cast<float>(pts[i].l);
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events.push_back(Event{phi, std::sqrt(sumI / sumSig), {e.x, e.y, e.z},
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pts[i].h, pts[i].k, pts[i].l});
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}
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}
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i = j;
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}
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// Frames per event is the phi_obs sampling: near 2 the reflections barely rock, so the angle
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// this refinement is fitted to is under-determined. It is a geometry count, so unlike an
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// intensity-weighted width it cannot be inflated by noise.
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logger.Info("Post-refine: {} multi-frame rocking events ({:.1f} frames per event)", events.size(),
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events.empty() ? 0.0 : static_cast<double>(event_frames) / events.size());
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if (static_cast<int>(events.size()) < settings.min_events) return result;
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// The rotation-scale fit further down is a single scalar whose whole point is how the residual
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// varies ALONG the sweep, so it keeps every event. The cap below ranks by I/sigma, and on the
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// crystals that have a stage fault the strong events sit in the middle of the sweep - the part
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// that still indexes - so a capped set would leave the ends unrepresented in exactly the fit that
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// has to see them.
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const std::vector<Event> scale_events = events;
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constexpr size_t MAX_EVENTS = 20000;
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if (events.size() > MAX_EVENTS) {
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std::nth_element(events.begin(), events.begin() + MAX_EVENTS, events.end(),
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[](const Event &a, const Event &b) { return a.weight > b.weight; });
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events.resize(MAX_EVENTS);
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}
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// ---- GEOMETRY REFINEMENT: the XtalOptimizer-equivalent, done as TWO SEPARATE
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// cross-validated steps rather than one joint fit (the same lesson as integration: refining the
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// profile width and the scale jointly fails, refining them separately works). Each step is committed
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// only if it lowers a HELD-OUT (deterministic split-half) residual - otherwise that part of the
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// geometry is left at nominal ("quit when things go wrong"):
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// Step A: cell scale + rotation axis from phi_obs (distance-independent excitation residual).
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// Step B: detector distance + beam centre from the observed spot positions, with the cell FIXED at
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// step A (so the positional residual is no longer degenerate with the cell scale).
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// Detector tilt is held fixed (gauge-coupled to orientation on a single crystal). ----
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if (settings.refine_geometry) {
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const gemmi::CrystalSystem sys =
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(settings.crystal_system == gemmi::CrystalSystem::Trigonal) ? gemmi::CrystalSystem::Hexagonal
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: settings.crystal_system;
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const double ax0[3] = {ax.x, ax.y, ax.z};
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const double lambda_l = lambda;
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const double rot3 = nominal_geom.GetPoniRot3_rad();
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const double pixel_mm = nominal_geom.GetPixelSize_mm();
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const double det_rot[2] = {nominal_geom.GetPoniRot1_rad(), nominal_geom.GetPoniRot2_rad()};
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const UnitCell r0 = reference_latt.GetUnitCell();
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// Deterministic split of the reflections into a fit half and a held-out half. Avalanche-mix the
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// hkl hash so the split bit is decorrelated from the LSB - a plain h+k+l parity collides with the
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// lattice centering condition (e.g. an I-centred lattice has h+k+l even for EVERY present
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// reflection, so a parity split would leave the validation half empty).
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auto is_val = [](int h, int k, int l) {
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unsigned u = static_cast<unsigned>(h) * 2654435761u + static_cast<unsigned>(k) * 2246822519u
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+ static_cast<unsigned>(l) * 3266489917u;
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u ^= u >> 15; u *= 2246822519u; u ^= u >> 13;
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return (u & 1u) != 0u;
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};
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enum Subset { FIT, VAL, ALL };
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auto in = [&](int h, int k, int l, Subset s) {
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return s == ALL || (is_val(h, k, l) == (s == VAL)); };
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// ===== Step A: cell scale s + rotation axis from phi_obs =====
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auto excit_cost = [&](Subset s, double sc, const double axv[3]) {
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double c = 0.0; int n = 0;
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for (const auto &ev : events) {
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if (!in(ev.h, ev.k, ev.l, s)) continue;
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ScaleAxisExcitationResidual r(lambda_l, ev.phi_obs, 1.0, ev.e_ref);
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double sd = sc, av[3] = {axv[0], axv[1], axv[2]}, resid = 0.0;
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r(&sd, av, &resid); c += resid * resid; ++n;
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}
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return n ? c / n : 0.0;
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};
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auto solve_scale_axis = [&](Subset s, double &s_out, double ax_out[3]) {
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double sc = 1.0, axv[3] = {ax0[0], ax0[1], ax0[2]};
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ceres::Problem p;
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for (const auto &ev : events) {
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if (!in(ev.h, ev.k, ev.l, s)) continue;
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p.AddResidualBlock(new ceres::AutoDiffCostFunction<ScaleAxisExcitationResidual, 1, 1, 3>(
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new ScaleAxisExcitationResidual(lambda_l, ev.phi_obs, settings.excitation_weight, ev.e_ref)),
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new ceres::CauchyLoss(0.02), &sc, axv);
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}
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p.SetParameterLowerBound(&sc, 0, 0.9); p.SetParameterUpperBound(&sc, 0, 1.1);
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for (int j = 0; j < 3; ++j) { p.SetParameterLowerBound(axv, j, ax0[j] - 0.05);
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p.SetParameterUpperBound(axv, j, ax0[j] + 0.05); }
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ceres::Solver::Options o; o.linear_solver_type = ceres::DENSE_QR; o.max_num_iterations = 50;
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o.num_threads = std::max(1, settings.num_threads); o.logging_type = ceres::LoggingType::SILENT;
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ceres::Solver::Summary sum; ceres::Solve(o, &p, &sum);
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s_out = sc; ax_out[0] = axv[0]; ax_out[1] = axv[1]; ax_out[2] = axv[2];
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return sum.IsSolutionUsable();
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};
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double s_fit = 1.0, ax_fit[3];
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const bool convA = solve_scale_axis(FIT, s_fit, ax_fit);
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const double cvA_nom = excit_cost(VAL, 1.0, ax0);
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const double cvA_ref = excit_cost(VAL, s_fit, ax_fit);
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// Commit the cell scale only for a small, credible move: a well-calibrated header needs < ~0.6 %,
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// so a > 1 % scale is a red flag (on multi-lattice / noisy data the excitation fit is biased the
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// same way in every cross-validation fold, so the relative-improvement gate cannot catch it).
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result.cell_refined = convA && cvA_ref < 0.98 * cvA_nom && std::fabs(s_fit - 1.0) < 0.01;
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double s = 1.0, axv[3] = {ax0[0], ax0[1], ax0[2]};
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if (result.cell_refined) solve_scale_axis(ALL, s, axv); // commit: re-fit on all data
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const double axlen = std::sqrt(axv[0]*axv[0] + axv[1]*axv[1] + axv[2]*axv[2]);
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const double axdev = std::acos(std::clamp((axv[0]*ax0[0]+axv[1]*ax0[1]+axv[2]*ax0[2])
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/ std::max(1e-9, axlen), -1.0, 1.0)) * 180.0 / PI;
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logger.Info("Post-refine GEOM step A (cell/axis): s = {:.5f}, rot-axis {:.3f} deg, held-out excit "
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"{:.3e} -> {:.3e} => {}", s, axdev, cvA_nom, cvA_ref,
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result.cell_refined ? "COMMIT" : "reject (kept nominal cell)");
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// ===== Goniometer rotation SCALE k, its own one-parameter fit on the same rocking events =====
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// The angles stored in the file are the COMMANDED ones, so a stage that turned k times as far
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// is invisible in the header. Nothing else here can represent it: the cell scale, the axis
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// direction, the distance and the beam are all orthogonal to a rotation MAGNITUDE error. Fitted
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// after step A so the cell scale and the axis direction are fixed at their committed values and
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// k is the only free quantity.
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const double u[3] = {axv[0] / axlen, axv[1] / axlen, axv[2] / axlen};
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double phi_c = 0.0, phi_lo = scale_events[0].phi_obs, phi_hi = scale_events[0].phi_obs;
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for (const auto &ev : scale_events) {
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phi_c += ev.phi_obs;
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phi_lo = std::min(phi_lo, ev.phi_obs);
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phi_hi = std::max(phi_hi, ev.phi_obs);
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}
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phi_c /= static_cast<double>(scale_events.size());
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const double sweep_deg = (phi_hi - phi_lo) * 180.0 / PI;
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// The reference reciprocal vector turned to the sweep centre, at the committed cell scale. The
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// angle then enters the fit measured FROM that centre. A constant crystal missetting about the
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// spindle is k with a slope in phi, so measuring the angle from the goniometer's zero instead
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// lets a missetting leak into k with gain <phi>/<phi^2> - which depends only on where the sweep
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// happens to sit. On a short sweep starting near zero that gain is enormous: a 0.14 deg
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// missetting on a 10 deg wedge fakes 1.4 % of k. Referred to the sweep centre the leak is
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// identically zero at any width, and no parameter has to be added to get it.
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// The residual is closed-form in k, so this is a one-parameter minimisation rather than a
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// solver problem. A rotation preserves length, so |p_lab| = |e_mid| whatever k is, and only
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// the z component moves; Rodrigues gives it exactly:
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//
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// r(k) = C + A cos(a k) - B sin(a k) = C + R cos(a k + psi)
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// C = lambda |e|^2 / 2 + u_z (u.e), A = e_z - u_z (u.e), B = (u x e)_z, a = phi_obs - phi_c
|
|
//
|
|
// which is the same function the residual functor computes, to the last bit. Handing 8 million
|
|
// one-parameter residual blocks to Ceres instead cost tens of millions of allocations and a
|
|
// dense factorisation per iteration, for a fit that a scan over a bounded interval settles.
|
|
// Coefficients are computed in double and stored narrowed: their rounding perturbs the
|
|
// minimiser by ~1e-10, and k is carried downstream as a float.
|
|
struct ScaleTerm { float a, C, R, psi; };
|
|
std::vector<ScaleTerm> terms(scale_events.size());
|
|
std::vector<int> fifth_of(scale_events.size());
|
|
const double aa_c[3] = {-phi_c * u[0], -phi_c * u[1], -phi_c * u[2]};
|
|
ParallelChunks(static_cast<int>(scale_events.size()), nthreads, [&](int lo, int hi) {
|
|
for (int e = lo; e < hi; ++e) {
|
|
const double p[3] = {scale_events[e].e_ref[0] / s, scale_events[e].e_ref[1] / s,
|
|
scale_events[e].e_ref[2] / s};
|
|
double em[3];
|
|
ceres::AngleAxisRotatePoint(aa_c, p, em);
|
|
const double ue = u[0] * em[0] + u[1] * em[1] + u[2] * em[2];
|
|
const double e2 = em[0] * em[0] + em[1] * em[1] + em[2] * em[2];
|
|
const double C = 0.5 * lambda_l * e2 + u[2] * ue;
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|
const double A = em[2] - u[2] * ue;
|
|
const double B = u[0] * em[1] - u[1] * em[0];
|
|
terms[e] = ScaleTerm{static_cast<float>(scale_events[e].phi_obs - phi_c),
|
|
static_cast<float>(C), static_cast<float>(std::hypot(A, B)),
|
|
static_cast<float>(std::atan2(B, A))};
|
|
fifth_of[e] = std::clamp(static_cast<int>(
|
|
5.0 * (scale_events[e].phi_obs - phi_lo) / std::max(1e-9, phi_hi - phi_lo)), 0, 4);
|
|
}
|
|
});
|
|
|
|
// Robust-loss scale from the scatter the events actually have: it varies by more than a decade
|
|
// between datasets, so any fixed constant is either inert or throws away real data. Taken once,
|
|
// over every event, so the all-data fit and every jackknife fold share it.
|
|
const auto residual_at = [&](const ScaleTerm &t, double k) {
|
|
return static_cast<double>(t.C)
|
|
+ static_cast<double>(t.R) * std::cos(static_cast<double>(t.a) * k + t.psi);
|
|
};
|
|
double rms = 0.0;
|
|
for (const auto &t : terms) {
|
|
const double r = residual_at(t, 1.0);
|
|
rms += r * r;
|
|
}
|
|
rms = std::sqrt(rms / static_cast<double>(terms.size()));
|
|
const double huber_delta = std::max(1e-12, 2.0 * rms);
|
|
const double huber_d2 = huber_delta * huber_delta;
|
|
|
|
// Ceres minimises half the sum of the loss applied to the SQUARED residual, so that is what is
|
|
// reproduced here. One pass yields the five per-fifth partial sums, which serve the all-data
|
|
// fit and all five leave-a-fifth-out folds together.
|
|
const auto cost_by_fifth = [&](double k) {
|
|
std::array<double, 5> total{};
|
|
std::mutex mx;
|
|
ParallelChunks(static_cast<int>(terms.size()), nthreads, [&](int lo, int hi) {
|
|
std::array<double, 5> acc{};
|
|
for (int e = lo; e < hi; ++e) {
|
|
const double r = residual_at(terms[e], k);
|
|
const double s2 = r * r;
|
|
acc[fifth_of[e]] += (s2 <= huber_d2) ? s2
|
|
: (2.0 * huber_delta * std::sqrt(s2) - huber_d2);
|
|
}
|
|
std::unique_lock ul(mx);
|
|
for (int j = 0; j < 5; ++j) total[j] += acc[j];
|
|
});
|
|
return total;
|
|
};
|
|
|
|
// Scan the interval Ceres was bounded to, then close in. No event's phase can move by more than
|
|
// a fraction of a period over an interval this narrow, so the objective has no structure the
|
|
// grid could step over; the refinement is only there to place the minimum precisely.
|
|
constexpr int SCALE_GRID = 101;
|
|
constexpr double SCALE_K_LO = 0.95, SCALE_K_HI = 1.05;
|
|
std::vector<std::array<double, 5>> grid(SCALE_GRID);
|
|
for (int g = 0; g < SCALE_GRID; ++g)
|
|
grid[g] = cost_by_fifth(SCALE_K_LO + (SCALE_K_HI - SCALE_K_LO) * g / (SCALE_GRID - 1));
|
|
auto solve_scale = [&](int drop_fifth) {
|
|
const auto total = [&](const std::array<double, 5> &f) {
|
|
double t = 0.0;
|
|
for (int j = 0; j < 5; ++j)
|
|
if (j != drop_fifth) t += f[j];
|
|
return t;
|
|
};
|
|
int best = 0;
|
|
for (int g = 1; g < SCALE_GRID; ++g)
|
|
if (total(grid[g]) < total(grid[best])) best = g;
|
|
const double step = (SCALE_K_HI - SCALE_K_LO) / (SCALE_GRID - 1);
|
|
double a = std::max(SCALE_K_LO, SCALE_K_LO + step * (best - 1));
|
|
double b = std::min(SCALE_K_HI, SCALE_K_LO + step * (best + 1));
|
|
// Golden section: the objective is smooth but its curvature jumps wherever an event
|
|
// crosses the Huber knee, which a derivative method would have to cope with.
|
|
constexpr double INV_PHI = 0.6180339887498949;
|
|
double c = b - INV_PHI * (b - a), d = a + INV_PHI * (b - a);
|
|
double fc = total(cost_by_fifth(c)), fd = total(cost_by_fifth(d));
|
|
while (b - a > 1e-9) {
|
|
if (fc < fd) { b = d; d = c; fd = fc; c = b - INV_PHI * (b - a); fc = total(cost_by_fifth(c)); }
|
|
else { a = c; c = d; fc = fd; d = a + INV_PHI * (b - a); fd = total(cost_by_fifth(d)); }
|
|
}
|
|
return 0.5 * (a + b);
|
|
};
|
|
const double k_fit = solve_scale(-1);
|
|
result.rotation_scale = k_fit;
|
|
|
|
// ----- Whether to COMMIT it. A stage fault is rare - 36 of 37 rotation datasets sit at 1.0000
|
|
// on a direct scan - and a 1 % angle correction applied to a healthy dataset would damage it
|
|
// silently, so every test below has to pass.
|
|
// Preconditions: below these the fit is reported but never acted on. Under ~30 deg of sweep k
|
|
// entangles with the axis direction and 10-20 deg truncations of a perfect dataset wander by
|
|
// +-0.6 %; a screening wedge must not trigger a correction.
|
|
constexpr int MIN_SCALE_EVENTS = 5000;
|
|
constexpr double MIN_SCALE_SWEEP_DEG = 30.0;
|
|
// T1 significance: 0.5 % is 18 sigma on the between-dataset scatter of healthy stages
|
|
// (robust sd 2.8e-4) and still 3.5x below the one measured fault.
|
|
constexpr double ROTATION_SCALE_TOL = 0.005;
|
|
// T2 relevance: the misorientation the error produces at each end of the sweep. A large k over
|
|
// a short sweep moves nothing and is not worth correcting.
|
|
constexpr double MIN_SCALE_END_ERROR_DEG = 0.5;
|
|
// T3 uniformity: a stage error is a ramp present in EVERY part of the sweep, so dropping any
|
|
// fifth of it must leave the same k. A second lattice that dominates ONE END of the sweep -
|
|
// exactly what happens where the primary stops indexing - fakes a k indistinguishable from a
|
|
// real fault on T1 and T2, and is the reason this test is not optional. It replaces the
|
|
// hkl-hash split used elsewhere here, which cannot see it: both halves of that split sit at
|
|
// the same angles, so anything structured in phi survives in both folds.
|
|
constexpr double MIN_SCALE_JACKKNIFE_FRAC = 0.5;
|
|
const double end_error_deg = std::fabs(k_fit - 1.0) * sweep_deg / 2.0;
|
|
const bool enough_data = static_cast<int>(scale_events.size()) >= MIN_SCALE_EVENTS
|
|
&& sweep_deg >= MIN_SCALE_SWEEP_DEG;
|
|
const bool big_enough = enough_data && std::fabs(k_fit - 1.0) >= ROTATION_SCALE_TOL
|
|
&& end_error_deg >= MIN_SCALE_END_ERROR_DEG;
|
|
double jackknife = 1.0;
|
|
if (big_enough)
|
|
for (int f = 0; f < 5; ++f)
|
|
jackknife = std::min(jackknife, (solve_scale(f) - 1.0) / (k_fit - 1.0));
|
|
result.rotation_scale_suspect = big_enough && jackknife >= MIN_SCALE_JACKKNIFE_FRAC;
|
|
logger.Info("Post-refine rotation SCALE: k = {:.5f} over {:.0f} deg of sweep centred on {:.1f} "
|
|
"deg ({} events): end error {:.2f} deg, leave-a-fifth-out {:.2f} => {}",
|
|
k_fit, sweep_deg, phi_c * 180.0 / PI, scale_events.size(), end_error_deg, jackknife,
|
|
result.rotation_scale_suspect ? "COMMIT"
|
|
: !enough_data ? "report only (too little sweep or too few events)"
|
|
: "reject (kept the stored angles)");
|
|
if (result.rotation_scale_suspect)
|
|
logger.Warning("Goniometer rotation scale looks off by {:+.2f} % (fitted {:.5f}): the stage "
|
|
"appears to have turned {} than the angles stored in the file, which are the "
|
|
"COMMANDED values. This is a hardware calibration fault, not a data problem - "
|
|
"left uncorrected it inflates mosaicity, biases the cell and loses "
|
|
"high-resolution reflections",
|
|
100.0 * (k_fit - 1.0), k_fit, k_fit > 1.0 ? "further" : "less far");
|
|
|
|
// Cell (scale s, shape fixed) as the XtalResidual parameter blocks p0/p1/p2, held CONSTANT in step B.
|
|
double p0[3] = {0, 0, 0}, p1[3] = {0, 0, 0}, p2[3] = {0, 0, 0};
|
|
double beta = r0.beta;
|
|
switch (sys) {
|
|
case gemmi::CrystalSystem::Tetragonal:
|
|
LatticeToRodriguesAndLengths_GS(reference_latt, p0, p1);
|
|
p1[0] = (p1[0] + p1[1]) / 2.0; break;
|
|
case gemmi::CrystalSystem::Cubic:
|
|
LatticeToRodriguesAndLengths_GS(reference_latt, p0, p1);
|
|
p1[0] = (p1[0] + p1[1] + p1[2]) / 3.0; break;
|
|
case gemmi::CrystalSystem::Hexagonal:
|
|
LatticeToRodriguesAndLengths_Hex(reference_latt, p0, p1); break;
|
|
case gemmi::CrystalSystem::Monoclinic:
|
|
LatticeToRodriguesLengthsBeta_Mono(reference_latt, p0, p1, beta);
|
|
p2[0] = beta; break;
|
|
case gemmi::CrystalSystem::Orthorhombic:
|
|
LatticeToRodriguesAndLengths_GS(reference_latt, p0, p1); break;
|
|
default:
|
|
LatticeToRodriguesAndLengths_GS(reference_latt, p0, p1);
|
|
p2[0] = r0.alpha * PI / 180.0; p2[1] = r0.beta * PI / 180.0; p2[2] = r0.gamma * PI / 180.0; break;
|
|
}
|
|
for (int j = 0; j < 3; ++j) p1[j] *= s; // apply the committed cell scale
|
|
double rot_vec[3] = {axv[0], axv[1], axv[2]}; // committed (or nominal) axis
|
|
|
|
// ===== Step B: detector distance + beam from the observed positions, cell fixed =====
|
|
std::vector<const Partial *> obs;
|
|
for (const auto &pp : pts)
|
|
if (std::isfinite(pp.obs_x) && std::isfinite(pp.obs_y)) obs.push_back(&pp);
|
|
constexpr size_t MAX_OBS = 20000;
|
|
if (obs.size() > MAX_OBS) {
|
|
std::nth_element(obs.begin(), obs.begin() + MAX_OBS, obs.end(),
|
|
[](const Partial *a, const Partial *b) {
|
|
return a->I / std::max(1e-9, a->sigma) > b->I / std::max(1e-9, b->sigma); });
|
|
obs.resize(MAX_OBS);
|
|
}
|
|
result.obs_used = static_cast<int>(obs.size());
|
|
const double beam_x0 = nominal_geom.GetBeamX_pxl(), beam_y0 = nominal_geom.GetBeamY_pxl();
|
|
const double dist0 = nominal_geom.GetDetectorDistance_mm();
|
|
auto pos_cost = [&](Subset s, const double beam[2], const double dist[1]) {
|
|
double c = 0.0; int n = 0;
|
|
for (const Partial *pp : obs) {
|
|
if (!in(pp->h, pp->k, pp->l, s)) continue;
|
|
XtalResidual r(pp->obs_x, pp->obs_y, lambda_l, pixel_mm, rot3, pp->angle_rad,
|
|
pp->h, pp->k, pp->l, sys);
|
|
double resid[3] = {0, 0, 0};
|
|
r(beam, dist, det_rot, rot_vec, p0, p1, p2, resid);
|
|
c += resid[0]*resid[0] + resid[1]*resid[1] + resid[2]*resid[2]; ++n;
|
|
}
|
|
return n ? c / n : 0.0;
|
|
};
|
|
auto solve_detector = [&](Subset s, double beam_out[2], double &dist_out) {
|
|
double beam[2] = {beam_x0, beam_y0}, dist[1] = {dist0};
|
|
ceres::Problem p;
|
|
for (const Partial *pp : obs) {
|
|
if (!in(pp->h, pp->k, pp->l, s)) continue;
|
|
p.AddResidualBlock(new ceres::AutoDiffCostFunction<XtalResidual, 3, 2, 1, 2, 3, 3, 3, 3>(
|
|
new XtalResidual(pp->obs_x, pp->obs_y, lambda_l, pixel_mm, rot3, pp->angle_rad,
|
|
pp->h, pp->k, pp->l, sys)),
|
|
new ceres::CauchyLoss(0.02), beam, dist,
|
|
const_cast<double *>(det_rot), rot_vec, p0, p1, p2);
|
|
p.SetParameterBlockConstant(const_cast<double *>(det_rot));
|
|
p.SetParameterBlockConstant(rot_vec);
|
|
p.SetParameterBlockConstant(p0); p.SetParameterBlockConstant(p1); p.SetParameterBlockConstant(p2);
|
|
}
|
|
if (p.NumResidualBlocks() == 0) { beam_out[0] = beam_x0; beam_out[1] = beam_y0; dist_out = dist0; return false; }
|
|
p.SetParameterLowerBound(dist, 0, dist0 * 0.95); p.SetParameterUpperBound(dist, 0, dist0 * 1.05);
|
|
for (int j = 0; j < 2; ++j) { p.SetParameterLowerBound(beam, j, beam[j] - 15.0);
|
|
p.SetParameterUpperBound(beam, j, beam[j] + 15.0); }
|
|
ceres::Solver::Options o; o.linear_solver_type = ceres::DENSE_QR; o.max_num_iterations = 60;
|
|
o.num_threads = std::max(1, settings.num_threads); o.logging_type = ceres::LoggingType::SILENT;
|
|
ceres::Solver::Summary sum; ceres::Solve(o, &p, &sum);
|
|
beam_out[0] = beam[0]; beam_out[1] = beam[1]; dist_out = dist[0];
|
|
return sum.IsSolutionUsable();
|
|
};
|
|
double beam[2] = {beam_x0, beam_y0}, dist = dist0;
|
|
if (obs.size() >= static_cast<size_t>(settings.min_events)) {
|
|
double beam_fit[2], dist_fit;
|
|
const bool convB = solve_detector(FIT, beam_fit, dist_fit);
|
|
const double b_nom[2] = {beam_x0, beam_y0}, d_nom[1] = {dist0};
|
|
const double b_ref[2] = {beam_fit[0], beam_fit[1]}, d_ref[1] = {dist_fit};
|
|
const double cvB_nom = pos_cost(VAL, b_nom, d_nom);
|
|
const double cvB_ref = pos_cost(VAL, b_ref, d_ref);
|
|
// Commit the detector geometry only for a small, credible move: distance < 1 % (a calibrated
|
|
// header needs < ~0.6 %). A larger move is the red flag for an unreliable fit - typically a
|
|
// second lattice whose spots bias every cross-validation fold identically, so the relative
|
|
// "it improved" gate is blind to it and pulls a spurious distance<->cell pair (the radial
|
|
// degeneracy) far off. The absolute size of the move discriminates a genuine header correction
|
|
// from that failure far better than the absolute residual, which real marginal (noisy / iced)
|
|
// data shares with the multi-lattice case.
|
|
const bool in_bounds = std::fabs(dist_fit - dist0) < 0.01 * dist0
|
|
&& std::hypot(beam_fit[0] - beam_x0, beam_fit[1] - beam_y0) < 15.0;
|
|
result.detector_refined = convB && cvB_ref < 0.98 * cvB_nom && in_bounds;
|
|
if (result.detector_refined) { double bo[2]; solve_detector(ALL, bo, dist); beam[0] = bo[0]; beam[1] = bo[1]; }
|
|
logger.Info("Post-refine GEOM step B (distance/beam): dist {:.3f} -> {:.3f} mm, beam "
|
|
"({:.2f},{:.2f}) -> ({:.2f},{:.2f}), held-out pos {:.3e} -> {:.3e} => {}",
|
|
dist0, result.detector_refined ? dist : dist0, beam_x0, beam_y0,
|
|
result.detector_refined ? beam[0] : beam_x0, result.detector_refined ? beam[1] : beam_y0,
|
|
cvB_nom, cvB_ref, result.detector_refined ? "COMMIT" : "reject (kept nominal detector)");
|
|
} else {
|
|
logger.Info("Post-refine GEOM step B: only {} positional observations - skipped", obs.size());
|
|
}
|
|
|
|
// Assemble the committed geometry.
|
|
UnitCell cellA = r0;
|
|
if (result.cell_refined) { cellA.a = static_cast<float>(r0.a * s); cellA.b = static_cast<float>(r0.b * s);
|
|
cellA.c = static_cast<float>(r0.c * s); }
|
|
result.cell = cellA;
|
|
result.distance_after_mm = dist;
|
|
result.beam_x_before_px = beam_x0; result.beam_x_after_px = beam[0];
|
|
result.beam_y_before_px = beam_y0; result.beam_y_after_px = beam[1];
|
|
result.events_used = static_cast<int>(events.size());
|
|
result.ok = result.cell_refined || result.detector_refined;
|
|
if (!result.ok)
|
|
logger.Info("Post-refine GEOM: neither step passed cross-validation - geometry left at nominal");
|
|
return result;
|
|
}
|
|
|
|
return result; // refine_geometry is the only supported mode; nothing refined otherwise
|
|
} catch (...) {
|
|
result.ok = false;
|
|
return result;
|
|
}
|
|
}
|
|
|