Files
Jungfraujoch/tests/CalcBraggPredictionTest.cpp
T
leonarski_fandClaude Opus 5.5 09bb88d4d4 Bragg prediction on the CPU grows its buffer instead of stopping at 20000
BraggPrediction::Calc and BraggPredictionRot::Calc stopped filling at
max_reflections (kPredictionCapacity = 20000), silently, inside the h/k/l
walk - so a frame that predicted more kept whichever reflections the walk
reached first, while the GPU predictors grow their buffer (GrowCapacity) and
keep them all. A large cell therefore merged a different reflection set on a
CPU-only build (the macOS/Windows viewer path, or CUDA_VISIBLE_DEVICES=) than
on a GPU one.

Both CPU predictors now double the buffer when the walk fills it, so they
return the same set as the GPU; output_limit and TruncateToOutput are
unchanged and remain the one cap on what leaves Calc, on both paths.

Tests: BraggPrediction_GrowsPastStartingCapacity ([portable], CPU only) - a
large cell predicting 28k (still) / 54k (rotation) reflections on one frame
gives exactly what a buffer large enough from the outset gives, and an
output_limit keeps the best-recorded half. BraggPrediction_CPU_GPU_
consistency_large_cell - the same frame on CPU and GPU: 28384/28384 and
53671/53671 matched by hkl, positions within 0.1 px. Both fail on the old
code (count == 20000).

Validation (CPU build): four in-house sets md5-identical to the base. A
dense rotation set from the private arm predicted 72.0M (20000 x 3600
frames) before and 235.9M now, against the GPU's 235.9M; it ingests
218.65M partials, as the GPU does, and now reaches the GPU's cell, space
group and merging statistics, where the capped CPU run settled on a
different lattice. Cost on the CPU: 72.5 GB peak RSS (17.5 GB before),
44.5 min wall on a shared machine (7.2 min before).

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01D1G8gJVAy6gp1K5Dz3NE5C
2026-09-28 18:15:50 +02:00

780 lines
33 KiB
C++

// SPDX-FileCopyrightText: 2024 Filip Leonarski, Paul Scherrer Institute <filip.leonarski@psi.ch>
// SPDX-License-Identifier: GPL-3.0-only
#include <catch2/catch_all.hpp>
#include "../image_analysis/bragg_prediction/BraggPrediction.h"
#include "../common/JFJochMath.h"
#include <iostream>
#include "../image_analysis/SensorAbsorption.h"
#include "../image_analysis/bragg_prediction/BraggPredictionRot.h"
#include "../image_analysis/bragg_prediction/RockingSlice.h"
#include <map>
#include <set>
// The flight-path term is a zero-parameter prediction: a NIST attenuation coefficient, the stated
// sample-to-detector distance, and Beer-Lambert. Nothing about it is fitted, so it can be checked
// against the tables it is computed from rather than against any measurement.
TEST_CASE("BraggPrediction_FlightPathAttenuation", "[air_path]") {
using sensor_absorption::FlightPathAttenuation;
constexpr double D_mm = 160.0;
auto lambda_of = [](double keV) { return 12.39842 / keV; };
auto air = [&](double keV) {
return FlightPathAttenuation::Build(FlightPathMedium::Air, D_mm, lambda_of(keV));
};
// Attenuation length of dry air, as D/L at a known distance. These follow from the NIST dry-air
// mass attenuation coefficients and 1.205e-3 g/cm^3, and span four decades over the corpus's
// energy range: L is 8.2 m at 18 keV but only 8.9 cm at 3.8 keV.
CHECK(air(18.0).d_over_L == Catch::Approx(0.01959).epsilon(0.01));
CHECK(air(12.4).d_over_L == Catch::Approx(0.05351).epsilon(0.01));
CHECK(air(3.76).d_over_L == Catch::Approx(1.7972).epsilon(0.01));
// The argon K edge at 3.2029 keV is in the table and is a real step: argon is 1.28% of air by
// mass but dominates its absorption here, so interpolating straight across it would understate
// the correction in exactly the regime where the correction is largest.
CHECK(air(3.21).d_over_L > air(3.19).d_over_L * 1.05f);
const auto a18 = air(18.0);
// Normalised at normal incidence: head-on is untouched, by construction rather than by rounding.
CHECK(a18.Factor(1.0f) == 1.0f);
// Always >= 1 and monotone in the obliquity, because a reflection that arrives at a larger angle
// crossed strictly more of the medium.
float prev = 1.0f;
for (double alpha_deg : {10.0, 20.0, 30.0, 40.0, 50.0, 55.0}) {
const float f = a18.Factor(static_cast<float>(std::cos(alpha_deg * PI / 180.0)));
CHECK(f > prev);
prev = f;
}
const float cos55 = static_cast<float>(std::cos(55.0 * PI / 180.0));
// 18 keV over 160 mm at 55 degrees: +1.5%.
CHECK(a18.Factor(cos55) == Catch::Approx(1.0147).epsilon(0.002));
// It runs the other way to the sensor term at the same angle: the sensor makes an oblique
// reflection read high, the medium makes it read low, and neither is the other's undoing.
const auto qe = sensor_absorption::SensorQE::Build("Si", 450.0, lambda_of(18.0));
CHECK(qe.Factor(cos55) < 1.0f);
CHECK(a18.Factor(cos55) > 1.0f);
// HELIUM is why a long-wavelength station is usable at all: at 3.8 keV it attenuates some three
// orders of magnitude less than air, so the same geometry that costs a factor of several in air
// costs a fraction of a per cent in helium. It is NOT vacuum, and is not modelled as one.
const auto he = FlightPathAttenuation::Build(FlightPathMedium::Helium, D_mm, lambda_of(3.76));
CHECK(he.d_over_L > 0.0f);
CHECK(he.d_over_L < air(3.76).d_over_L / 100.0f);
CHECK(he.Factor(cos55) > 1.0f);
CHECK(he.Factor(cos55) < 1.01f);
// VACUUM leaves every intensity exactly untouched, at every angle - bit-identical to applying
// no correction at all.
const auto vac = FlightPathAttenuation::Build(FlightPathMedium::Vacuum, D_mm, lambda_of(3.76));
CHECK(vac.d_over_L == 0.0f);
CHECK(vac.Factor(1.0f) == 1.0f);
CHECK(vac.Factor(0.5f) == 1.0f);
CHECK(vac.Factor(0.1f) == 1.0f);
// Same for a file that states no distance or no wavelength.
CHECK(FlightPathAttenuation::Build(FlightPathMedium::Air, 0.0, lambda_of(12.4)).d_over_L == 0.0f);
CHECK(FlightPathAttenuation::Build(FlightPathMedium::Air, D_mm, 0.0).d_over_L == 0.0f);
// What the report quotes as the worth of the assumption. On an untilted detector the correction
// is a pure function of resolution, so its whole effect on merged data is a Wilson-B shift; the
// sign is negative because lifting the high-angle data flattens the fall-off. Measured on real
// data at three geometries, this predicts the observed shift to within 8%.
const double dB_hard = air(13.0).WilsonBShift_A2(1.28, 50.0, lambda_of(13.0));
const double dB_soft = air(3.76).WilsonBShift_A2(3.02, 50.0, lambda_of(3.76));
CHECK(dB_hard < 0.0);
CHECK(std::fabs(dB_hard) < 1.0); // hard X-rays: nothing a user could read off the data
CHECK(dB_soft < -5.0); // long wavelength: the dominant correction in the run
CHECK(std::fabs(dB_soft) > std::fabs(dB_hard) * 10.0);
// Vacuum is worth exactly nothing, which is what makes the report line meaningful.
CHECK(vac.WilsonBShift_A2(3.02, 50.0, lambda_of(3.76)) == 0.0);
}
TEST_CASE("BraggPrediction_11keV", "[portable]") {
DiffractionExperiment experiment(DetJF4M());
experiment.DetectorDistance_mm(100.0).BeamX_pxl(1500.0).BeamY_pxl(1000.0)
.IncidentEnergy_keV(11.0);
DiffractionGeometry geom = experiment.GetDiffractionGeometry();
CrystalLattice lattice(Coord{20, 10, 0}, Coord{-20, 40, 0},
Coord{0, 0, 200});
BraggPredictionSettings settings{
.high_res_A = 2.0,
.ewald_dist_cutoff = 0.001,
.max_h = 40, .max_k = 40, .max_l = 40
};
BraggPrediction prediction;
int count = prediction.Calc(experiment, lattice, settings);
REQUIRE(count > 0);
for (int i = 0; i < count; i++) {
auto r = prediction.GetReflections().at(i);
auto recip = r.h * lattice.Astar() + r.k * lattice.Bstar() + r.l * lattice.Cstar();
REQUIRE(std::abs(r.h) < settings.max_h );
REQUIRE(std::abs(r.k) < settings.max_k );
REQUIRE(std::abs(r.l) < settings.max_l );
REQUIRE(r.d >= settings.high_res_A);
REQUIRE(r.d == Catch::Approx(1/std::sqrt(recip * recip)).margin(0.01f));
REQUIRE(r.dist_ewald == Catch::Approx(std::abs(geom.DistFromEwaldSphere(recip))).epsilon(1e-4));
auto [x,y] = geom.RecipToDetector(recip);
REQUIRE(r.predicted_x == Catch::Approx(x).margin(0.01));
REQUIRE(r.predicted_y == Catch::Approx(y).margin(0.01));
}
}
TEST_CASE("BraggPrediction_15keV") {
DiffractionExperiment experiment(DetJF4M());
experiment.DetectorDistance_mm(100.0).BeamX_pxl(1500.0).BeamY_pxl(1000.0)
.IncidentEnergy_keV(15.0);
DiffractionGeometry geom = experiment.GetDiffractionGeometry();
CrystalLattice lattice(Coord{20, 10, 0}, Coord{-20, 40, 0},
Coord{0, 0, 200});
BraggPredictionSettings settings{
.high_res_A = 2.0,
.ewald_dist_cutoff = 0.001,
.max_h = 40, .max_k = 40, .max_l = 40
};
BraggPrediction prediction;
int count = prediction.Calc(experiment, lattice, settings);
REQUIRE(count > 0);
for (int i = 0; i < count; i++) {
auto r = prediction.GetReflections().at(i);
auto recip = r.h * lattice.Astar() + r.k * lattice.Bstar() + r.l * lattice.Cstar();
REQUIRE(std::abs(r.h) < settings.max_h );
REQUIRE(std::abs(r.k) < settings.max_k );
REQUIRE(std::abs(r.l) < settings.max_l );
REQUIRE(r.d >= settings.high_res_A);
REQUIRE(r.d == Catch::Approx(1/std::sqrt(recip * recip)).margin(0.01f));
REQUIRE(r.dist_ewald == Catch::Approx(std::abs(geom.DistFromEwaldSphere(recip))).epsilon(1e-3));
auto [x,y] = geom.RecipToDetector(recip);
REQUIRE(r.predicted_x == Catch::Approx(x).margin(0.01));
REQUIRE(r.predicted_y == Catch::Approx(y).margin(0.01));
}
}
TEST_CASE("BraggPrediction_Rot1_Rot2", "[portable]") {
DiffractionExperiment experiment(DetJF4M());
experiment.DetectorDistance_mm(100.0).BeamX_pxl(1500.0).BeamY_pxl(1000.0)
.PoniRot1_rad(2.0/180.0 * PI).PoniRot2_rad(3.0/180.0 * PI)
.IncidentEnergy_keV(11.0);
DiffractionGeometry geom = experiment.GetDiffractionGeometry();
CrystalLattice lattice(Coord{20, 10, 0}, Coord{-20, 40, 0},
Coord{0, 0, 200});
BraggPredictionSettings settings{
.high_res_A = 2.0,
.ewald_dist_cutoff = 0.001,
.max_h = 40, .max_k = 40, .max_l = 40
};
BraggPrediction prediction;
int count = prediction.Calc(experiment, lattice, settings);
REQUIRE(count > 0);
for (int i = 0; i < count; i++) {
auto r = prediction.GetReflections().at(i);
auto recip = r.h * lattice.Astar() + r.k * lattice.Bstar() + r.l * lattice.Cstar();
REQUIRE(std::abs(r.h) < settings.max_h );
REQUIRE(std::abs(r.k) < settings.max_k );
REQUIRE(std::abs(r.l) < settings.max_l );
REQUIRE(r.d >= settings.high_res_A);
REQUIRE(r.d == Catch::Approx(1/std::sqrt(recip * recip)).margin(0.01f));
REQUIRE(r.dist_ewald == Catch::Approx(std::abs(geom.DistFromEwaldSphere(recip))).epsilon(1e-4));
auto [x,y] = geom.RecipToDetector(recip);
REQUIRE(r.predicted_x == Catch::Approx(x).margin(0.01));
REQUIRE(r.predicted_y == Catch::Approx(y).margin(0.01));
}
}
TEST_CASE("BraggPrediction_backscattering") {
DiffractionExperiment experiment(DetJF9M());
experiment.DetectorDistance_mm(120.0).BeamX_pxl(1500.0).BeamY_pxl(1000.0)
.IncidentEnergy_keV(3.0/WVL_1A_IN_KEV);
// Orthogonal basis, sufficient to test parity rules
CrystalLattice lattice(
Coord{40, 0, 0},
Coord{0, 50, 0},
Coord{0, 0, 60}
);
BraggPredictionSettings settings{
.high_res_A = 3.0f,
.ewald_dist_cutoff = 0.1f, // Very large cutoff, to be able to see as many reflections as possible
.max_h = 50, .max_k = 50, .max_l = 50
};
BraggPrediction pred;
int count = pred.Calc(experiment, lattice, settings);
REQUIRE(count > 0);
for (const auto& r : pred.GetReflections()) {
if (r.d == 0) break;
REQUIRE(r.d > 3.0 / sqrt(2.0));
}
}
TEST_CASE("BraggPrediction_systematic_absences", "[portable]") {
DiffractionExperiment experiment(DetJF4M());
experiment.DetectorDistance_mm(120.0).BeamX_pxl(1500.0).BeamY_pxl(1000.0)
.IncidentEnergy_keV(12.0);
// Orthogonal basis, sufficient to test parity rules
CrystalLattice lattice(
Coord{40, 0, 0},
Coord{0, 50, 0},
Coord{0, 0, 60}
);
BraggPredictionSettings settings{
.high_res_A = 3.0f,
.ewald_dist_cutoff = 0.1f, // Very large cutoff, to be able to see as many reflections as possible
.max_h = 50, .max_k = 50, .max_l = 50
};
BraggPrediction pred;
SECTION("I centering") {
// 1) Body-centered I: reflections with h+k+l odd must be absent
settings.centering = 'I';
int count_I = pred.Calc(experiment, lattice, settings);
REQUIRE(count_I > 0);
for (const auto& r : pred.GetReflections()) {
if (r.d == 0) break; // ignore unfilled tail if any
REQUIRE(((r.h + r.k + r.l) % 2) == 0);
}
}
SECTION ("F centering") {
// 2) Face-centered F: h,k,l all even or all odd
settings.centering = 'F';
int count_F = pred.Calc(experiment, lattice, settings);
REQUIRE(count_F > 0);
for (const auto& r : pred.GetReflections()) {
if (r.d == 0) break;
const bool he = (r.h & 1) == 0, ke = (r.k & 1) == 0, le = (r.l & 1) == 0;
const bool all_even = he && ke && le;
const bool all_odd = (!he) && (!ke) && (!le);
REQUIRE((all_even || all_odd));
}
}
SECTION("R centering") {
settings.centering = 'R';
int count_R = pred.Calc(experiment, lattice, settings);
REQUIRE(count_R > 0);
// R (hexagonal setting): -h + k + l = 3n
for (const auto& r : pred.GetReflections()) {
if (r.d == 0) break;
int cond = (-r.h + r.k + r.l) % 3;
if (cond < 0) cond += 3;
REQUIRE(cond == 0);
}
}
}
TEST_CASE("RockingSliceCentroid_TruncatedNormalMean", "[rocking_slice]") {
// The closed form against a direct quadrature of the slice, on a frame that holds the centre, one on
// the curve's flank and one on its far tail.
const float sigma = 0.004f, half_wedge = 0.0015f, c1 = 1.0f / (std::sqrt(2.0f) * sigma);
for (float phi : {0.0f, 0.001f, -0.006f, 0.012f}) {
double sw = 0.0, stw = 0.0;
for (int i = 0; i <= 20000; ++i) {
const double t = phi - half_wedge + 2.0 * half_wedge * i / 20000.0;
const double w = std::exp(-t * t / (2.0 * sigma * sigma));
sw += w; stw += t * w;
}
const float partiality = (std::erf((phi + half_wedge) * c1) - std::erf((phi - half_wedge) * c1)) / 2.0f;
INFO("phi " << phi);
CHECK(RockingSliceCentroid_rad(phi, half_wedge, c1, partiality) == Catch::Approx(stw / sw).margin(2e-6));
}
CHECK(RockingSliceCentroid_rad(0.0f, half_wedge, c1, 0.3f) == 0.0f);
}
TEST_CASE("BraggPredictionRot_PartialWalksAlongItsRing", "[rocking_slice]") {
// Each rotation frame predicts a partial where the frame's slice of its rocking curve puts it: the
// exact-condition position walked along the Debye ring. Over the frames of one reflection the
// predicted positions therefore stay at one distance from the beam and move monotonically along
// the ring; a prediction at the exact condition would be the same point on every frame.
DiffractionExperiment experiment(DetJF4M());
experiment.DetectorDistance_mm(100.0).BeamX_pxl(1100.0).BeamY_pxl(1000.0).IncidentEnergy_keV(12.4);
const GoniometerAxis axis("omega", 0.0f, 0.1f, Coord(-1, 0, 0), {});
experiment.Goniometer(axis);
const CrystalLattice lattice(Coord{40, 0, 0}, Coord{0, 50, 0}, Coord{0, 0, 60});
BraggPredictionSettings settings{.high_res_A = 2.5, .ewald_dist_cutoff = 0.0015,
.max_h = 20, .max_k = 25, .max_l = 30,
.wedge_deg = 0.1f, .mosaicity_deg = 0.1f};
const float bx = 1100.0f, by = 1000.0f;
std::map<std::tuple<int, int, int>, std::vector<std::pair<float, float>>> track; // (radius, azimuth)
BraggPredictionRot pred;
for (int frame = 0; frame < 300; ++frame) {
const auto latt = lattice.Multiply(axis.GetTransformationAngle(frame * 0.1f));
const int n = pred.Calc(experiment, latt, settings);
for (int i = 0; i < n; ++i) {
const auto &r = pred.GetReflections().at(i);
if (r.zeta > 0.3f) continue;
const float dx = r.predicted_x - bx, dy = r.predicted_y - by;
track[{r.h, r.k, r.l}].emplace_back(std::hypot(dx, dy), std::atan2(dy, dx));
}
}
int tested = 0;
for (const auto &[hkl, pts] : track) {
if (pts.size() < 20) continue;
float rmin = pts[0].first, rmax = pts[0].first;
float along_first = 0.0f, along_last = 0.0f;
int sign_changes = 0;
float prev_step = 0.0f;
for (size_t j = 0; j < pts.size(); ++j) {
rmin = std::min(rmin, pts[j].first);
rmax = std::max(rmax, pts[j].first);
const float along = (pts[j].second - pts[0].second) * pts[0].first; // px along the ring
if (j == 0) along_first = along;
along_last = along;
if (j > 0) {
const float step = (pts[j].second - pts[j - 1].second);
if (step * prev_step < 0.0f) ++sign_changes;
if (step != 0.0f) prev_step = step;
}
}
INFO("hkl " << std::get<0>(hkl) << " " << std::get<1>(hkl) << " " << std::get<2>(hkl) << " frames " << pts.size());
CHECK(rmax - rmin < 0.05f); // stays on its ring
CHECK(std::fabs(along_last - along_first) > 0.1f); // but walks along it
CHECK(sign_changes == 0); // in one direction
++tested;
}
CHECK(tested > 20);
}
// A large cell, and a frame that predicts more reflections than the prediction buffer starts with, on
// both the still and the rotation path. Shared by the CPU test below and the CPU/GPU parity test.
namespace {
DiffractionExperiment LargeCellExperiment() {
DiffractionExperiment experiment(DetJF4M());
experiment.DetectorDistance_mm(100.0).BeamX_pxl(1500.0).BeamY_pxl(1000.0)
.IncidentEnergy_keV(12.0)
.Goniometer(GoniometerAxis("omega", 0.0f, 1.0f, Coord(-1, 0, 0), {}));
return experiment;
}
CrystalLattice LargeCell() {
return CrystalLattice(Coord{150, 10, 0}, Coord{-10, 140, 5}, Coord{0, -5, 160});
}
BraggPredictionSettings LargeCellSettings() {
return BraggPredictionSettings{
.high_res_A = 1.6,
.ewald_dist_cutoff = 0.004,
.max_h = 95, .max_k = 90, .max_l = 100,
.wedge_deg = 1.0f
};
}
}
TEST_CASE("BraggPrediction_GrowsPastStartingCapacity", "[portable]") {
// A frame predicting more than the buffer starts with must come back whole - the same reflections a
// buffer large enough from the outset returns - and not as whichever the h/k/l walk reached first.
const auto experiment = LargeCellExperiment();
const auto lattice = LargeCell();
const auto settings = LargeCellSettings();
BraggPrediction still_grown, still_large(1000000);
BraggPredictionRot rot_grown, rot_large(1000000);
const std::vector<std::pair<BraggPrediction *, BraggPrediction *>> pairs = {
{&still_grown, &still_large}, {&rot_grown, &rot_large}
};
for (const auto &[grown, large] : pairs) {
const int n_grown = grown->Calc(experiment, lattice, settings);
const int n_large = large->Calc(experiment, lattice, settings);
REQUIRE(n_grown > BraggPrediction::kPredictionCapacity);
REQUIRE(n_grown == n_large);
for (int i = 0; i < n_grown; i++) {
const auto &a = grown->GetReflections()[i];
const auto &b = large->GetReflections()[i];
REQUIRE(a.h == b.h);
REQUIRE(a.k == b.k);
REQUIRE(a.l == b.l);
REQUIRE(a.predicted_x == b.predicted_x);
REQUIRE(a.predicted_y == b.predicted_y);
}
// Where a limit applies, what is kept is the best-recorded part: no dropped reflection ranks above
// the worst kept one - by partiality on the rotation path, by excitation error on the still path.
const bool rotation = (grown == &rot_grown);
std::vector<Reflection> all(grown->GetReflections().begin(), grown->GetReflections().begin() + n_grown);
grown->output_limit = n_grown / 2;
const int n_kept = grown->Calc(experiment, lattice, settings);
REQUIRE(n_kept == n_grown / 2);
std::set<std::tuple<int, int, int, float>> kept;
float worst_partiality = 1.0f, worst_dist_ewald = 0.0f;
for (int i = 0; i < n_kept; i++) {
const auto &r = grown->GetReflections()[i];
kept.insert({r.h, r.k, r.l, r.delta_phi_deg});
worst_partiality = std::min(worst_partiality, r.partiality);
worst_dist_ewald = std::max(worst_dist_ewald, r.dist_ewald);
}
for (const auto &r : all) {
if (kept.contains({r.h, r.k, r.l, r.delta_phi_deg}))
continue;
if (rotation)
REQUIRE(r.partiality <= worst_partiality);
else
REQUIRE(r.dist_ewald >= worst_dist_ewald);
}
}
}
#ifdef JFJOCH_USE_CUDA
#include "../image_analysis/bragg_prediction/BraggPredictionGPU.h"
#include "../image_analysis/bragg_prediction/BraggPredictionRotGPU.h"
#include "../image_analysis/bragg_prediction/BraggPredictionRot.h"
#include <map>
#include <algorithm>
TEST_CASE("BraggPredictionGPU") {
DiffractionExperiment experiment(DetJF4M());
experiment.DetectorDistance_mm(100.0).BeamX_pxl(1500.0).BeamY_pxl(1000.0)
.IncidentEnergy_keV(13.0);
DiffractionGeometry geom = experiment.GetDiffractionGeometry();
CrystalLattice lattice(Coord{20, 10, 0}, Coord{-20, 40, 0},
Coord{0, 0, 200});
BraggPredictionSettings settings{
.high_res_A = 2.0,
.ewald_dist_cutoff = 0.001,
.max_h = 40, .max_k = 40, .max_l = 40
};
BraggPredictionGPU prediction;
int count = prediction.Calc(experiment, lattice, settings);
REQUIRE(count > 0);
for (int i = 0; i < count; i++) {
auto r = prediction.GetReflections().at(i);
auto recip = r.h * lattice.Astar() + r.k * lattice.Bstar() + r.l * lattice.Cstar();
REQUIRE(std::abs(r.h) < settings.max_h );
REQUIRE(std::abs(r.k) < settings.max_k );
REQUIRE(std::abs(r.l) < settings.max_l );
REQUIRE(r.d >= settings.high_res_A);
REQUIRE(r.d == Catch::Approx(1/std::sqrt(recip * recip)).margin(0.01f));
REQUIRE(r.dist_ewald == Catch::Approx(std::abs(geom.DistFromEwaldSphere(recip))).epsilon(2e-2));
auto [x,y] = geom.RecipToDetector(recip);
REQUIRE(r.predicted_x == Catch::Approx(x).margin(0.05));
REQUIRE(r.predicted_y == Catch::Approx(y).margin(0.05));
}
}
TEST_CASE("BraggPredictionGPU_Rot1_Rot2") {
DiffractionExperiment experiment(DetJF4M());
experiment.DetectorDistance_mm(100.0).BeamX_pxl(1500.0).BeamY_pxl(1000.0)
.PoniRot1_rad(2.0/180.0 * PI).PoniRot2_rad(3.0/180.0 * PI)
.IncidentEnergy_keV(11.0);
DiffractionGeometry geom = experiment.GetDiffractionGeometry();
CrystalLattice lattice(Coord{20, 10, 0}, Coord{-20, 40, 0},
Coord{0, 0, 200});
BraggPredictionSettings settings{
.high_res_A = 2.0,
.ewald_dist_cutoff = 0.001,
.max_h = 40, .max_k = 40, .max_l = 40
};
BraggPredictionGPU prediction;
int count = prediction.Calc(experiment, lattice, settings);
REQUIRE(count > 0);
for (int i = 0; i < count; i++) {
auto r = prediction.GetReflections().at(i);
auto recip = r.h * lattice.Astar() + r.k * lattice.Bstar() + r.l * lattice.Cstar();
REQUIRE(std::abs(r.h) < settings.max_h );
REQUIRE(std::abs(r.k) < settings.max_k );
REQUIRE(std::abs(r.l) < settings.max_l );
REQUIRE(r.d >= settings.high_res_A);
REQUIRE(r.d == Catch::Approx(1/std::sqrt(recip * recip)).margin(0.01f));
REQUIRE(r.dist_ewald == Catch::Approx(std::abs(geom.DistFromEwaldSphere(recip))).epsilon(1e-3));
auto [x,y] = geom.RecipToDetector(recip);
REQUIRE(r.predicted_x == Catch::Approx(x).margin(0.05));
REQUIRE(r.predicted_y == Catch::Approx(y).margin(0.05));
}
}
TEST_CASE("BraggPredictionGPU_systematic_absences") {
DiffractionExperiment experiment(DetJF4M());
experiment.DetectorDistance_mm(120.0).BeamX_pxl(1500.0).BeamY_pxl(1000.0)
.IncidentEnergy_keV(12.0);
CrystalLattice lattice(
Coord{40, 0, 0},
Coord{0, 50, 0},
Coord{0, 0, 60}
);
BraggPredictionSettings settings{
.high_res_A = 3.0f,
.ewald_dist_cutoff = 0.1f,
.max_h = 50, .max_k = 50, .max_l = 50
};
BraggPredictionGPU pred;
SECTION ("I centering") {
// 1) Body-centered I
settings.centering = 'I';
int count_I = pred.Calc(experiment, lattice, settings);
REQUIRE(count_I > 0);
for (const auto& r : pred.GetReflections()) {
if (r.d == 0) break;
REQUIRE(((r.h + r.k + r.l) % 2) == 0);
}
}
SECTION ("F centering") {
// 2) Face-centered F
settings.centering = 'F';
int count_F = pred.Calc(experiment, lattice, settings);
REQUIRE(count_F > 0);
for (const auto& r : pred.GetReflections()) {
if (r.d == 0) break;
const bool he = (r.h & 1) == 0, ke = (r.k & 1) == 0, le = (r.l & 1) == 0;
const bool all_even = he && ke && le;
const bool all_odd = (!he) && (!ke) && (!le);
REQUIRE((all_even || all_odd));
}
}
SECTION("R centering") {
settings.centering = 'R';
int count_R = pred.Calc(experiment, lattice, settings);
REQUIRE(count_R > 0);
// R (hexagonal setting): -h + k + l = 3n
for (const auto& r : pred.GetReflections()) {
if (r.d == 0) break;
int cond = (-r.h + r.k + r.l) % 3;
if (cond < 0) cond += 3;
REQUIRE(cond == 0);
}
}
}
TEST_CASE("BraggPredictionGPU_backscattering") {
DiffractionExperiment experiment(DetJF9M());
experiment.DetectorDistance_mm(120.0).BeamX_pxl(1500.0).BeamY_pxl(1000.0)
.IncidentEnergy_keV(3.0/WVL_1A_IN_KEV);
// Orthogonal basis, sufficient to test parity rules
CrystalLattice lattice(
Coord{40, 0, 0},
Coord{0, 50, 0},
Coord{0, 0, 60}
);
BraggPredictionSettings settings{
.high_res_A = 3.0f,
.ewald_dist_cutoff = 0.1f, // Very large cutoff, to be able to see as many reflections as possible
.max_h = 50, .max_k = 50, .max_l = 50
};
BraggPredictionGPU pred;
int count = pred.Calc(experiment, lattice, settings);
REQUIRE(count > 0);
for (const auto& r : pred.GetReflections()) {
if (r.d == 0) break;
REQUIRE(r.d > 3.0 / sqrt(2.0));
}
}
TEST_CASE("BraggPrediction_CPU_GPU_consistency_tilted") {
// Verify CPU and GPU implementations produce identical results with tilted detector
DiffractionExperiment experiment(DetJF4M());
experiment.DetectorDistance_mm(100.0).BeamX_pxl(1500.0).BeamY_pxl(1000.0)
.PoniRot1_rad(0.04).PoniRot2_rad(-0.025)
.IncidentEnergy_keV(12.0);
CrystalLattice lattice(Coord{30, 10, 0}, Coord{-15, 45, 0}, Coord{0, 0, 150});
BraggPredictionSettings settings{
.high_res_A = 2.0,
.ewald_dist_cutoff = 0.0015,
.max_h = 30, .max_k = 30, .max_l = 30
};
BraggPrediction cpu_pred;
BraggPredictionGPU gpu_pred;
int cpu_count = cpu_pred.Calc(experiment, lattice, settings);
int gpu_count = gpu_pred.Calc(experiment, lattice, settings);
REQUIRE(cpu_count > 0);
REQUIRE(gpu_count > 0);
// Build map of GPU reflections by hkl
std::map<std::tuple<int,int,int>, const Reflection*> gpu_refl_map;
for (int i = 0; i < gpu_count; ++i) {
const auto& r = gpu_pred.GetReflections().at(i);
gpu_refl_map[{r.h, r.k, r.l}] = &r;
}
// Check that each CPU reflection has a matching GPU reflection
int matched = 0;
float min_corr = 1.0f;
float max_flight = 1.0f;
for (int i = 0; i < cpu_count; ++i) {
const auto& cpu_r = cpu_pred.GetReflections().at(i);
auto key = std::make_tuple(cpu_r.h, cpu_r.k, cpu_r.l);
auto it = gpu_refl_map.find(key);
if (it != gpu_refl_map.end()) {
const auto& gpu_r = *it->second;
CHECK(cpu_r.predicted_x == Catch::Approx(gpu_r.predicted_x).margin(0.1));
CHECK(cpu_r.predicted_y == Catch::Approx(gpu_r.predicted_y).margin(0.1));
CHECK(cpu_r.d == Catch::Approx(gpu_r.d).margin(0.01));
// Both halves of the correction are part of the prediction, not a downstream product:
// the sensor-efficiency term lived on the CPU path alone for a while because nothing here
// compared it, and it is now a field of its own - so it is compared as a field of its own.
CHECK(cpu_r.prescaling_corr == Catch::Approx(gpu_r.prescaling_corr).epsilon(1e-4));
CHECK(cpu_r.qe_corr == Catch::Approx(gpu_r.qe_corr).epsilon(1e-4));
CHECK(cpu_r.flight_corr == Catch::Approx(gpu_r.flight_corr).epsilon(1e-4));
CHECK(cpu_r.image_scale_corr == Catch::Approx(gpu_r.image_scale_corr).epsilon(1e-4));
min_corr = std::min(min_corr, cpu_r.qe_corr);
max_flight = std::max(max_flight, cpu_r.flight_corr);
matched++;
}
}
// Most reflections should match (allow for some numerical differences at boundaries)
CHECK(matched > cpu_count * 0.95);
// ... and the comparison above must not be vacuous: on this geometry (320 um Si at 12 keV,
// reflections out to 2 A) the sensor correction is several per cent, so a qe_corr that stayed
// at 1 on both sides would mean the correction had been dropped from BOTH paths. It is checked
// on qe_corr and not on prescaling_corr, which no longer carries it.
CHECK(min_corr < 0.99f);
// The same for the air term, which runs the other way: at 12 keV over this distance the air
// correction reaches a few tenths of a per cent at the detector corner, so an flight_corr pinned at
// 1 on both sides would mean it had been dropped from BOTH paths rather than agreeing.
CHECK(max_flight > 1.0f);
}
TEST_CASE("BraggPredictionRot_CPU_GPU_consistency_tilted") {
// The rotation counterpart of the test above. Same purpose: every per-reflection quantity the
// two implementations both produce has to agree - the Lorentz-polarization factor and the sensor
// efficiency each in their own field, so neither can hide behind the other in a product.
DiffractionExperiment experiment(DetJF4M());
experiment.DetectorDistance_mm(100.0).BeamX_pxl(1500.0).BeamY_pxl(1000.0)
.PoniRot1_rad(0.04).PoniRot2_rad(-0.025)
.IncidentEnergy_keV(12.0)
.Goniometer(GoniometerAxis("omega", 0.0f, 0.1f, Coord(-1, 0, 0), {}));
CrystalLattice lattice(Coord{30, 10, 0}, Coord{-15, 45, 0}, Coord{0, 0, 150});
BraggPredictionSettings settings{
.high_res_A = 2.0,
.ewald_dist_cutoff = 0.0015,
.max_h = 30, .max_k = 30, .max_l = 30
};
BraggPredictionRot cpu_pred;
BraggPredictionRotGPU gpu_pred;
int cpu_count = cpu_pred.Calc(experiment, lattice, settings);
int gpu_count = gpu_pred.Calc(experiment, lattice, settings);
REQUIRE(cpu_count > 0);
REQUIRE(gpu_count > 0);
std::map<std::tuple<int,int,int>, const Reflection*> gpu_refl_map;
for (int i = 0; i < gpu_count; ++i) {
const auto& r = gpu_pred.GetReflections().at(i);
gpu_refl_map[{r.h, r.k, r.l}] = &r;
}
int matched = 0;
float min_corr = 1.0f;
float max_flight = 1.0f;
for (int i = 0; i < cpu_count; ++i) {
const auto& cpu_r = cpu_pred.GetReflections().at(i);
auto it = gpu_refl_map.find(std::make_tuple(cpu_r.h, cpu_r.k, cpu_r.l));
if (it != gpu_refl_map.end()) {
const auto& gpu_r = *it->second;
CHECK(cpu_r.predicted_x == Catch::Approx(gpu_r.predicted_x).margin(0.1));
CHECK(cpu_r.predicted_y == Catch::Approx(gpu_r.predicted_y).margin(0.1));
CHECK(cpu_r.d == Catch::Approx(gpu_r.d).margin(0.01));
CHECK(cpu_r.prescaling_corr == Catch::Approx(gpu_r.prescaling_corr).epsilon(1e-3));
CHECK(cpu_r.qe_corr == Catch::Approx(gpu_r.qe_corr).epsilon(1e-3));
CHECK(cpu_r.flight_corr == Catch::Approx(gpu_r.flight_corr).epsilon(1e-3));
min_corr = std::min(min_corr, cpu_r.qe_corr);
max_flight = std::max(max_flight, cpu_r.flight_corr);
matched++;
}
}
CHECK(matched > cpu_count * 0.95);
CHECK(min_corr < 0.99f);
CHECK(max_flight > 1.0f);
}
TEST_CASE("BraggPrediction_CPU_GPU_consistency_large_cell") {
// A frame predicting more than kPredictionCapacity: both paths grow their buffer, so both predict the
// same reflections. The CPU used to stop at the capacity and return the first 20000 of the walk.
const auto experiment = LargeCellExperiment();
const auto lattice = LargeCell();
const auto settings = LargeCellSettings();
BraggPrediction still_cpu;
BraggPredictionGPU still_gpu;
BraggPredictionRot rot_cpu;
BraggPredictionRotGPU rot_gpu;
const std::vector<std::pair<BraggPrediction *, BraggPrediction *>> pairs = {
{&still_cpu, &still_gpu}, {&rot_cpu, &rot_gpu}
};
for (const auto &[cpu, gpu] : pairs) {
const int cpu_count = cpu->Calc(experiment, lattice, settings);
const int gpu_count = gpu->Calc(experiment, lattice, settings);
REQUIRE(cpu_count > BraggPrediction::kPredictionCapacity);
REQUIRE(gpu_count > BraggPrediction::kPredictionCapacity);
// Keyed by hkl and, on the rotation path, by the side of the frame centre, which separates the
// two rocking solutions one hkl can have. A still has one solution per hkl.
const bool rotation = (cpu == &rot_cpu);
auto key = [rotation](const Reflection &r) {
return std::make_tuple(r.h, r.k, r.l, rotation && r.delta_phi_deg > 0);
};
std::map<std::tuple<int, int, int, bool>, const Reflection *> gpu_map;
for (int i = 0; i < gpu_count; i++)
gpu_map[key(gpu->GetReflections()[i])] = &gpu->GetReflections()[i];
int matched = 0;
for (int i = 0; i < cpu_count; i++) {
const auto &c = cpu->GetReflections()[i];
auto it = gpu_map.find(key(c));
if (it == gpu_map.end())
continue;
CHECK(c.predicted_x == Catch::Approx(it->second->predicted_x).margin(0.1));
CHECK(c.predicted_y == Catch::Approx(it->second->predicted_y).margin(0.1));
matched++;
}
// The same set up to float rounding at the acceptance edges.
CHECK(matched >= cpu_count - cpu_count / 1000);
CHECK(matched >= gpu_count - gpu_count / 1000);
}
}
#endif