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Jungfraujoch/image_analysis/geom_refinement/XtalOptimizer.cpp
leonarski_fandClaude Opus 5 6e805f53c0
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image_analysis: stop paying for work that is thrown away
Three independent costs, each measured, none changing a result. Across the
37-crystal regression set the run time halves (median per crystal 2.0x, total
2.3x) and every crystal's merge statistics are unchanged.

The image copy back from the device moved the whole preprocessed frame - 72 MB
on a large detector, every frame, per worker - to serve a single host consumer
that reads only the strong pixels, at most a few hundred kilobytes of it. Give
the buffer a Gather() so that consumer asks for the values it actually wants (a
host loop on the CPU, a small kernel on the GPU), and copy the frame back only
when a CPU spot finder will genuinely read it. The copy the other way was worse:
it came from an unregistered vector, so the driver staged it through its own
pinned pool with a host-side memcpy on the calling thread, which does not overlap
and collapses under concurrency - 11.6 GB/s at one worker, 1.6 GB/s at eight.
That, not any hardware limit, is why throughput stopped improving past four to
eight workers. Pinning the decompression buffer once per worker fixes it: on a
18 Mpx dataset the image loop goes from 13.6 to 7.9 ms per image at 32 workers,
and 32 workers now beat 8 instead of losing to them.

Ceres was computing seventeen partial derivatives where five are free. The
per-image rotation refinement frees the beam and the orientation and holds
distance, detector angles, rotation axis and cell constant, but the cost
function declared all seven blocks, so every residual evaluated in Jet<17>
arithmetic. A residual exposing only the two free blocks - the same arithmetic,
the constants baked in - halves refinement, and it is exact rather than merely
close: dual coordinates evolve independently, so the residuals and the free
Jacobian columns are unchanged bit for bit.

The merge sorted an index array with a comparator that dereferenced a 1.6 GB
array of 72-byte records, i.e. a random walk over memory, single-threaded, twice
per two-pass run. Sorting a packed key instead is 2.4x. French-Wilson allocated
its integration scratch per reflection and ran serially; it now takes caller-owned
scratch and runs over chunks, 4.2x. The correction surfaces re-tested every
observation for usability and parity on each of ~22 passes and re-allocated their
accumulators each time; bucket the indices once and hoist the buffers.

Also convert std::round to std::rint where the rounded value only ever enters a
squared residual. The tie rules differ - away from zero against to even - so this
is safe exactly where a tie flips the sign but not the magnitude, and unsafe
wherever the value becomes a Miller index; those sites keep std::round. Verified
over all 2^32 float bit patterns: 8388608 exact ties exist, and the squared
residual is bitwise equal for every one of them. Worth little on its own here,
because the rounding that dominates is in candidate refinement, where the value
is an index and the substitution is not available.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-08-01 21:35:28 +02:00

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// SPDX-FileCopyrightText: 2025 Filip Leonarski, Paul Scherrer Institute <filip.leonarski@psi.ch>
// SPDX-License-Identifier: GPL-3.0-only
#include "../../common/JFJochMath.h"
#include <algorithm>
#include <numeric>
#include <Eigen/Dense>
#include "XtalOptimizer.h"
#include "XtalResidual.h"
#include "ceres/ceres.h"
#include "ceres/rotation.h"
#include "LatticeReduction.h"
// Soft header prior on ONE beam-centre component (the spindle-parallel, gauge-weak one). Residual = w*(b - b0);
// the caller sets w so the prior behaves like a sigma-pixel restraint that competes with the (unit-weight)
// positional residuals - strong enough to pin the gauge direction, negligible in the well-constrained one.
struct BeamComponentPrior {
BeamComponentPrior(int component, double b0, double weight)
: component(component), b0(b0), weight(weight) {}
template<typename T>
bool operator()(const T *const beam, T *residual) const {
residual[0] = T(weight) * (beam[component] - T(b0));
return true;
}
int component;
double b0, weight;
};
struct XtalResidualRotationOnlyPrecomp {
XtalResidualRotationOnlyPrecomp(const Coord &recip_obs,
const CrystalLattice &latt,
double h, double k, double l)
: s_obs(recip_obs),
astar(latt.Astar()), bstar(latt.Bstar()), cstar(latt.Cstar()),
h(h), k(k), l(l) {
}
template<typename T>
bool operator()(const T *const rot_aa, T *residual) const {
const T astar_unrot[3] = {T(astar.x), T(astar.y), T(astar.z)};
const T bstar_unrot[3] = {T(bstar.x), T(bstar.y), T(bstar.z)};
const T cstar_unrot[3] = {T(cstar.x), T(cstar.y), T(cstar.z)};
T astar_rot[3], bstar_rot[3], cstar_rot[3];
ceres::AngleAxisRotatePoint(rot_aa, astar_unrot, astar_rot);
ceres::AngleAxisRotatePoint(rot_aa, bstar_unrot, bstar_rot);
ceres::AngleAxisRotatePoint(rot_aa, cstar_unrot, cstar_rot);
const Eigen::Matrix<T, 3, 1> s_pred(T(h) * astar_rot[0] + T(k) * bstar_rot[0] + T(l) * cstar_rot[0],
T(h) * astar_rot[1] + T(k) * bstar_rot[1] + T(l) * cstar_rot[1],
T(h) * astar_rot[2] + T(k) * bstar_rot[2] + T(l) * cstar_rot[2]
);
// Residual in reciprocal space
residual[0] = T(s_obs.x) - s_pred[0];
residual[1] = T(s_obs.y) - s_pred[1];
residual[2] = T(s_obs.z) - s_pred[2];
return true;
}
const Coord s_obs;
const Coord astar, bstar, cstar;
const double h, k, l;
};
// Regularizer: penalises ||rot_aa|| to prefer the smallest rotation that
// explains the data. Weight should be chosen in the same units as the
// reciprocal-space residuals (Å⁻¹ per radian). A value of ~0.010.1 is
// typically enough to break degeneracy without biasing the solution.
struct RotationNormRegularizer {
explicit RotationNormRegularizer(double weight) : weight(weight) {}
template<typename T>
bool operator()(const T *const rot_aa, T *residual) const {
residual[0] = T(weight) * rot_aa[0];
residual[1] = T(weight) * rot_aa[1];
residual[2] = T(weight) * rot_aa[2];
return true;
}
const double weight;
};
// Prior confidence weight per spot: how strong the spot is FOR ITS RESOLUTION. The frame's spots are
// ordered by resolution and cut into equal-count shells, and each intensity is divided by its shell
// median. Refinement needs the high-resolution spots (they carry the cell and distance information) and
// those are legitimately weaker, so a raw intensity weight would suppress exactly the wrong ones; the
// shell normalisation makes the weight resolution-neutral by construction.
//
// The weight enters as w^2 on the squared residual, w^2 = r/(1+r): the shell median contributes half,
// a 4x-median spot 0.8, a quarter-median spot 0.2. Weak spots still pull, they just do not drive. Unlike
// a robust loss this is a PRIOR - it never looks at the current residual, so it cannot mistake a genuine
// spot for an outlier when the starting geometry is far off and leave the fit unable to move.
static std::vector<double> SpotConfidenceWeights(const std::vector<SpotToSave> &spots) {
constexpr size_t spots_per_shell = 32;
std::vector<size_t> by_res(spots.size());
std::iota(by_res.begin(), by_res.end(), 0);
std::ranges::sort(by_res, {}, [&](size_t i) { return spots[i].d_A; });
const size_t nshells = std::max<size_t>(1, spots.size() / spots_per_shell);
std::vector<double> weight(spots.size());
std::vector<float> shell_intensity;
for (size_t s = 0; s < nshells; s++) {
const size_t begin = s * spots.size() / nshells;
const size_t end = (s + 1) * spots.size() / nshells;
shell_intensity.clear();
for (size_t i = begin; i < end; i++)
shell_intensity.push_back(spots[by_res[i]].intensity);
std::ranges::nth_element(shell_intensity, shell_intensity.begin() + shell_intensity.size() / 2);
const double median = std::max(1e-3f, shell_intensity[shell_intensity.size() / 2]);
for (size_t i = begin; i < end; i++) {
const double r = std::max(0.0f, spots[by_res[i]].intensity) / median;
weight[by_res[i]] = std::sqrt(r / (1.0 + r));
}
}
return weight;
}
bool XtalOptimizerInternal(XtalOptimizerData &data,
const std::vector<std::vector<SpotToSave>> &spots,
const float tolerance,
const int num_threads) {
try {
Coord vec0 = data.latt.Vec0();
Coord vec1 = data.latt.Vec1();
Coord vec2 = data.latt.Vec2();
double beta = data.latt.GetUnitCell().beta;
// Initial guess for the parameters
double beam[2] = {data.geom.GetBeamX_pxl(), data.geom.GetBeamY_pxl()};
double distance_mm = data.geom.GetDetectorDistance_mm();
double detector_rot[2] = {data.geom.GetPoniRot1_rad(), data.geom.GetPoniRot2_rad()};
ceres::Problem problem;
double latt_vec0[3] = {0.0, 0.0, 0.0};
double latt_vec1[3] = {0.0, 0.0, 0.0};
double latt_vec2[3] = {0.0, 0.0, 0.0};
double rot_vec[3] = {1, 0, 0};
switch (data.crystal_system) {
case gemmi::CrystalSystem::Orthorhombic:
LatticeToRodriguesAndLengths_GS(data.latt, latt_vec0, latt_vec1);
break;
case gemmi::CrystalSystem::Tetragonal:
LatticeToRodriguesAndLengths_GS(data.latt, latt_vec0, latt_vec1);
latt_vec1[0] = (latt_vec1[0] + latt_vec1[1]) / 2.0;
break;
case gemmi::CrystalSystem::Cubic:
LatticeToRodriguesAndLengths_GS(data.latt, latt_vec0, latt_vec1);
latt_vec1[0] = (latt_vec1[0] + latt_vec1[1] + latt_vec1[2]) / 3.0;
break;
case gemmi::CrystalSystem::Hexagonal:
LatticeToRodriguesAndLengths_Hex(data.latt, latt_vec0, latt_vec1);
break;
case gemmi::CrystalSystem::Monoclinic:
LatticeToRodriguesLengthsBeta_Mono(data.latt, latt_vec0, latt_vec1, beta);
latt_vec2[0] = beta;
latt_vec2[1] = 0.0;
latt_vec2[2] = 0.0;
break;
default:
// Triclinic: initialize a,b,c and α,β,γ from current unit cell
LatticeToRodriguesAndLengths_GS(data.latt, latt_vec0, latt_vec1);
auto uc = data.latt.GetUnitCell();
latt_vec2[0] = uc.alpha * PI / 180.0;
latt_vec2[1] = uc.beta * PI / 180.0;
latt_vec2[2] = uc.gamma * PI / 180.0;
break;
}
if (data.axis) {
rot_vec[0] = data.axis->GetAxis().x;
rot_vec[1] = data.axis->GetAxis().y;
rot_vec[2] = data.axis->GetAxis().z;
}
const float tolerance_sq = tolerance * tolerance;
// Per-image rotation refinement frees only the beam and the orientation and holds the other five
// blocks constant, so the seven-block residual makes Ceres differentiate 17 parameters to use 5.
// Where that is the configuration, use the reduced residual instead - identical fit, Jet<5>
// autodiff. Any other combination (stills also free the cell, the offline refiner frees distance
// and detector angles) keeps the general form below.
const bool beam_and_orientation_only = data.refine_beam_center
&& !data.refine_distance_mm
&& !data.refine_detector_angles
&& !data.refine_rotation_axis
&& !data.refine_unit_cell;
// Sum of w^2 over the spots that entered - the beam prior below is scaled by it so that its
// strength relative to the data is the same weighted or not. Equals the residual block count
// when the spots are unweighted.
double effective_spots = 0.0;
for (int i = 0; i < spots.size(); i++) {
if (spots[i].empty())
continue;
std::vector<double> weight; // empty = unweighted
if (data.weight_spots_by_confidence)
weight = SpotConfidenceWeights(spots[i]);
double angle_rad = 0.0;
std::optional<RotMatrix> rot_matr;
if (data.axis) {
const float angle_deg = data.axis->GetAngle_deg(i) + data.axis->GetWedge_deg() / 2.0;
angle_rad = angle_deg * PI / 180.0;
rot_matr = data.axis->GetTransformationAngle(angle_deg);
}
// Add residuals for each point
for (size_t j = 0; j < spots[i].size(); j++) {
const auto &pt = spots[i][j];
if (!data.index_ice_rings && pt.ice_ring)
continue;
Coord recip = pt.ReciprocalCoord(data.geom);
if (rot_matr)
recip = rot_matr.value() * recip;
double h_fp = recip * vec0;
double k_fp = recip * vec1;
double l_fp = recip * vec2;
double h = std::round(h_fp);
double k = std::round(k_fp);
double l = std::round(l_fp);
double norm_sq = (h - h_fp) * (h - h_fp) + (k - k_fp) * (k - k_fp) + (l - l_fp) * (l - l_fp);
if (norm_sq > tolerance_sq)
continue;
const double weight_sq = weight.empty() ? 1.0 : weight[j] * weight[j];
effective_spots += weight_sq;
const XtalResidual residual(pt.x, pt.y,
data.geom.GetWavelength_A(),
data.geom.GetPixelSize_mm(),
data.geom.GetPoniRot3_rad(),
angle_rad,
h, k, l,
data.crystal_system);
// Ceres has no per-residual weight; ScaledLoss(nullptr, a) multiplies the squared
// residual by the constant a, i.e. it applies a weight of sqrt(a) to the residual.
ceres::LossFunction *loss = weight.empty()
? nullptr
: new ceres::ScaledLoss(nullptr, weight_sq,
ceres::TAKE_OWNERSHIP);
if (beam_and_orientation_only)
problem.AddResidualBlock(
new ceres::AutoDiffCostFunction<XtalResidualBeamOrientation, 3, 2, 3>(
new XtalResidualBeamOrientation(residual, distance_mm, detector_rot,
rot_vec, latt_vec1, latt_vec2)),
loss,
beam,
latt_vec0
);
else
problem.AddResidualBlock(
new ceres::AutoDiffCostFunction<XtalResidual, 3, 2, 1, 2, 3, 3, 3, 3>(
new XtalResidual(residual)),
loss,
beam,
&distance_mm,
detector_rot,
rot_vec,
latt_vec0,
latt_vec1,
latt_vec2
);
}
}
if (problem.NumResidualBlocks() < data.min_spots)
return false;
if (!data.refine_beam_center)
problem.SetParameterBlockConstant(beam);
else if (data.axis) {
// Gauge handling (single-axis rotation): rotating the whole experiment about the spindle leaves every
// spot position unchanged, so the beam-centre component PARALLEL to the spindle is a null/gauge-weak
// direction. Refining it freely lets it wander (~+3 px) and absorb centroid systematics into a wrong
// beam that the co-refined orientation keeps position-consistent. Rather than freeze it (the beam
// does drift - it is only LaB6-monitored to ~a few px), RESTRAIN it toward the header with a soft
// prior: the gauge direction has ~zero data sensitivity so the prior pins it near the header, while a
// real, well-supported drift can still overcome it. The spindle is along a detector axis in standard
// geometry, so restrain the dominant of X / Y.
const Coord spindle = data.axis->GetAxis();
const int parallel = (std::fabs(spindle.x) >= std::fabs(spindle.y)) ? 0 : 1;
// Weight so the prior is a sigma_px-pixel restraint that competes with the positional residuals.
// k = d|recip|/d(beam_px) ~ pixel/(distance*lambda) [A^-1/px]; scaling by sqrt(#residuals) makes the
// prior's curvature ~ (1/9) of the well-constrained-data curvature at sigma_px=3, i.e. data wins the
// perpendicular direction, the prior wins the gauge one.
constexpr double sigma_px = 3.0;
const double k = data.geom.GetPixelSize_mm() / (distance_mm * data.geom.GetWavelength_A());
const double w = k * std::sqrt(effective_spots) / sigma_px;
problem.AddResidualBlock(
new ceres::AutoDiffCostFunction<BeamComponentPrior, 1, 2>(
new BeamComponentPrior(parallel, beam[parallel], w)),
nullptr, beam);
}
// Distance, detector angles, rotation axis and cell are parameter blocks only in the general
// seven-block residual; the reduced one bakes them in, so there is nothing left to configure.
if (!beam_and_orientation_only) {
if (!data.refine_distance_mm)
problem.SetParameterBlockConstant(&distance_mm);
else {
const double dist_range = 0.1;
problem.SetParameterLowerBound(&distance_mm, 0, distance_mm * (1.0 - dist_range));
problem.SetParameterUpperBound(&distance_mm, 0, distance_mm * (1.0 + dist_range));
}
if (!data.refine_detector_angles) {
problem.SetParameterBlockConstant(detector_rot);
} else {
const double rot_range = 3.0 / 180.0 * PI;
for (int i = 0; i < 2; ++i) {
problem.SetParameterLowerBound(detector_rot, i, detector_rot[i] - rot_range);
problem.SetParameterUpperBound(detector_rot, i, detector_rot[i] + rot_range);
}
}
if (!data.refine_rotation_axis) {
problem.SetParameterBlockConstant(rot_vec);
}
if (!data.refine_unit_cell) {
problem.SetParameterBlockConstant(latt_vec1);
problem.SetParameterBlockConstant(latt_vec2);
} else {
// Parameter bounds
// Lengths
for (int i = 0; i < 3; ++i) {
problem.SetParameterLowerBound(latt_vec1, i, data.min_length_A);
problem.SetParameterUpperBound(latt_vec1, i, data.max_length_A);
}
if (data.crystal_system == gemmi::CrystalSystem::Monoclinic) {
const double beta_lo = std::max(1e-6, PI * (data.min_angle_deg / 180.0));
const double beta_hi = std::min(PI - 1e-6, PI * (data.max_angle_deg / 180.0));
problem.SetParameterLowerBound(latt_vec2, 0, beta_lo);
problem.SetParameterUpperBound(latt_vec2, 0, beta_hi);
} else if (data.crystal_system == gemmi::CrystalSystem::Triclinic) {
// α, β, γ bounds (radians)
const double alo = PI * (data.min_angle_deg / 180.0);
const double ahi = PI * (data.max_angle_deg / 180.0);
for (int i = 0; i < 3; ++i) {
problem.SetParameterLowerBound(latt_vec2, i, alo);
problem.SetParameterUpperBound(latt_vec2, i, ahi);
}
} else {
// Orthorhombic / Tetragonal / Cubic / Hexagonal:
// latt_vec2 has no meaning for these systems — always freeze it.
problem.SetParameterBlockConstant(latt_vec2);
}
}
}
// Configure solver
ceres::Solver::Options options;
options.linear_solver_type = ceres::DENSE_QR;
options.minimizer_progress_to_stdout = false;
if (data.max_iterations > 0)
options.max_num_iterations = data.max_iterations;
else
options.max_solver_time_in_seconds = data.max_time;
options.logging_type = ceres::LoggingType::SILENT;
options.num_threads = num_threads; // usually 1 (called from many threads); caller may raise it
ceres::Solver::Summary summary;
// Run optimization
ceres::Solve(options, &problem, &summary);
// Only a genuine numerical failure is rejected here: a solve that ran out of iterations or
// out of time but still descended counts as usable, which is what the real-time caller
// relies on when it sets max_solver_time. Checked before anything is written back, so a
// failed refinement leaves data untouched rather than committing half a fit.
if (!summary.IsSolutionUsable())
return false;
if (data.refine_beam_center) {
data.beam_corr_x = data.geom.GetBeamX_pxl() - beam[0];
data.beam_corr_y = data.geom.GetBeamY_pxl() - beam[1];
data.geom.BeamX_pxl(beam[0]).BeamY_pxl(beam[1]);
}
if (data.refine_distance_mm)
data.geom.DetectorDistance_mm(distance_mm);
if (data.refine_detector_angles)
data.geom.PoniRot1_rad(detector_rot[0]).PoniRot2_rad(detector_rot[1]);
if (data.axis && data.refine_rotation_axis)
data.axis.value().Axis(Coord(rot_vec[0], rot_vec[1], rot_vec[2]));
if (data.crystal_system == gemmi::CrystalSystem::Orthorhombic)
data.latt = AngleAxisAndCellToLattice(latt_vec0, latt_vec1, PI / 2.0, PI / 2.0, PI / 2.0);
else if (data.crystal_system == gemmi::CrystalSystem::Tetragonal) {
latt_vec1[1] = latt_vec1[0];
data.latt = AngleAxisAndCellToLattice(latt_vec0, latt_vec1, PI / 2.0, PI / 2.0, PI / 2.0);
} else if (data.crystal_system == gemmi::CrystalSystem::Cubic) {
latt_vec1[1] = latt_vec1[0];
latt_vec1[2] = latt_vec1[0];
data.latt = AngleAxisAndCellToLattice(latt_vec0, latt_vec1, PI / 2.0, PI / 2.0, PI / 2.0);
} else if (data.crystal_system == gemmi::CrystalSystem::Hexagonal) {
latt_vec1[1] = latt_vec1[0];
data.latt = AngleAxisAndCellToLattice(latt_vec0, latt_vec1,PI / 2.0, PI / 2.0, 2.0 * PI / 3.0);
} else if (data.crystal_system == gemmi::CrystalSystem::Monoclinic) {
data.latt = AngleAxisAndCellToLattice(latt_vec0, latt_vec1, PI / 2.0, latt_vec2[0], PI / 2.0);
} else {
// Triclinic via the same generic builder
data.latt = AngleAxisAndCellToLattice(latt_vec0, latt_vec1, latt_vec2[0], latt_vec2[1], latt_vec2[2]);
}
return true;
} catch (...) {
// Convergence problems, likely not updated
return false;
}
}
bool XtalOptimizer(XtalOptimizerData &data, const std::vector<std::vector<SpotToSave>> &spots,
int num_threads) {
if (!XtalOptimizerInternal(data, spots, 0.3, num_threads))
return false;
XtalOptimizerInternal(data, spots, 0.2, num_threads);
return XtalOptimizerInternal(data, spots, 0.1, num_threads);
}
bool XtalOptimizerRotationOnly(XtalOptimizerData &data,
const std::vector<SpotToSave> &spots,
const float tolerance) {
try {
// Parameter: angle-axis for the extra rotation. Identity == {0,0,0}.
double rot_aa[3] = {0.0, 0.0, 0.0};
// Spot selection by current indexing (same approach as XtalOptimizerInternal)
const Coord a0 = data.latt.Vec0();
const Coord b0 = data.latt.Vec1();
const Coord c0 = data.latt.Vec2();
const float tol_sq = tolerance * tolerance;
ceres::Problem problem;
for (const auto &pt : spots) {
if (!data.index_ice_rings && pt.ice_ring)
continue;
// Compute fractional HKL using the CURRENT lattice
Coord recip_index = pt.ReciprocalCoord(data.geom);
if (data.axis.has_value())
recip_index = data.axis->GetTransformationAngle(pt.phi) * recip_index;
const double h_fp = static_cast<double>(recip_index * a0);
const double k_fp = static_cast<double>(recip_index * b0);
const double l_fp = static_cast<double>(recip_index * c0);
const double h = std::round(h_fp);
const double k = std::round(k_fp);
const double l = std::round(l_fp);
const double norm_sq =
(h - h_fp) * (h - h_fp) +
(k - k_fp) * (k - k_fp) +
(l - l_fp) * (l - l_fp);
if (norm_sq > static_cast<double>(tol_sq))
continue;
// s_obs must be in the same reference frame as the
// predicted reciprocal vector (h·a* + k·b* + l·c*), which is the
// phi=0 crystal frame. Apply the same goniometer back-rotation
// that was used above for the HKL assignment.
Coord s_obs = data.geom.DetectorToRecip(pt.x, pt.y);
if (data.axis.has_value())
s_obs = data.axis->GetTransformationAngle(pt.phi) * s_obs;
auto *cost =
new ceres::AutoDiffCostFunction<XtalResidualRotationOnlyPrecomp, 3, 3>(
new XtalResidualRotationOnlyPrecomp(s_obs, data.latt, h, k, l)
);
problem.AddResidualBlock(cost, nullptr, rot_aa);
}
if (problem.NumResidualBlocks() < data.min_spots)
return false;
// Regularization: prefer the smallest rotation correction that fits the
// data. This is essential when spots are nearly coplanar in reciprocal
// space (e.g. still images), where the rotation component perpendicular
// to the scattering plane is otherwise underdetermined.
// The weight is in Å⁻¹ rad⁻¹; tune relative to your typical residual.
{
const double reg_weight = 0.05; // e.g. 0.05
problem.AddResidualBlock(
new ceres::AutoDiffCostFunction<RotationNormRegularizer, 3, 3>(
new RotationNormRegularizer(reg_weight)),
nullptr, rot_aa);
}
ceres::Solver::Options options;
options.linear_solver_type = ceres::DENSE_QR;
options.minimizer_progress_to_stdout = false;
if (data.max_iterations > 0)
options.max_num_iterations = data.max_iterations;
else
options.max_solver_time_in_seconds = data.max_time;
options.logging_type = ceres::LoggingType::SILENT;
options.num_threads = 1;
ceres::Solver::Summary summary;
ceres::Solve(options, &problem, &summary);
if (!summary.IsSolutionUsable())
return false;
// Apply rotation to direct-lattice vectors.
// ceres::AngleAxisToRotationMatrix writes a **row-major** 3×3 matrix,
// and Eigen's << operator also fills row-by-row, so the assignment
// below is correct without any transposing.
//
// Note: for a pure orthogonal rotation R, R⁻ᵀ = R, so rotating the
// direct-lattice vectors (A, B, C) by R is exactly equivalent to
// rotating the reciprocal vectors (a*, b*, c*) by the same R. No
// transpose or inversion of R is needed here.
double R_raw[9];
ceres::AngleAxisToRotationMatrix(rot_aa, R_raw); // row-major 3x3
Eigen::Matrix3d R;
R << R_raw[0], R_raw[3], R_raw[6],
R_raw[1], R_raw[4], R_raw[7],
R_raw[2], R_raw[5], R_raw[8];
const Eigen::Vector3d A(a0.x, a0.y, a0.z);
const Eigen::Vector3d B(b0.x, b0.y, b0.z);
const Eigen::Vector3d C(c0.x, c0.y, c0.z);
const Eigen::Vector3d A2 = R * A;
const Eigen::Vector3d B2 = R * B;
const Eigen::Vector3d C2 = R * C;
data.latt = CrystalLattice(
Coord(static_cast<float>(A2.x()), static_cast<float>(A2.y()), static_cast<float>(A2.z())),
Coord(static_cast<float>(B2.x()), static_cast<float>(B2.y()), static_cast<float>(B2.z())),
Coord(static_cast<float>(C2.x()), static_cast<float>(C2.y()), static_cast<float>(C2.z()))
);
double theta = std::sqrt(rot_aa[0] * rot_aa[0] + rot_aa[1] * rot_aa[1] + rot_aa[2] * rot_aa[2]);
data.angle_corr = theta;
if (theta > 1e-6) {
Coord rot;
rot.x = rot_aa[0] / theta;
rot.y = rot_aa[1] / theta;
rot.z = rot_aa[2] / theta;
data.angle_axis = rot;
} else
data.angle_axis.reset();
return true;
} catch (...) {
return false;
}
}