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BraggPrediction: Add angle from Ewald sphere according to nXDS definition

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This commit is contained in:
leonarski_f
2026-03-05 19:00:22 +01:00
parent ad1e724bcf
commit 427d9c91cf
2 changed files with 61 additions and 3 deletions
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image_analysis/bragg_prediction/BraggPrediction.cpp
+30 -2
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@@ -37,8 +37,11 @@ int BraggPrediction::Calc(const DiffractionExperiment &experiment, const Crystal
float pixel_size = geom.GetPixelSize_mm();
float F = det_distance / pixel_size;
int i = 0;
const float epsilon = 1e-5f;
const float s0_sq = S0 * S0;
const float rad_to_deg = 180.0f / static_cast<float>(M_PI);
int i = 0;
for (int h = -settings.max_hkl; h <= settings.max_hkl; h++) {
// Precompute A* h contribution
@@ -74,6 +77,31 @@ int BraggPrediction::Calc(const DiffractionExperiment &experiment, const Crystal
float dist_ewald_sphere = std::fabs(S_len - one_over_wavelength);
if (dist_ewald_sphere <= settings.ewald_dist_cutoff ) {
const float s0_p0 = S0.x * recip_x + S0.y * recip_y + S0.z * recip_z;
const float val = s0_sq * recip_sq - s0_p0 * s0_p0;
float delta_phi_deg = NAN;
if (std::fabs(val) >= epsilon && s0_sq > epsilon) {
const float a_num = (s0_sq - 0.25f * recip_sq) * recip_sq;
if (a_num >= 0.0f) {
const float A = std::sqrt(a_num / val);
const float B = (A * s0_p0 + 0.5f * recip_sq) / s0_sq;
const float p_star_x = A * recip_x - B * S0.x;
const float p_star_y = A * recip_y - B * S0.y;
const float p_star_z = A * recip_z - B * S0.z;
const float p_star_sq = p_star_x * p_star_x + p_star_y * p_star_y + p_star_z * p_star_z;
const float denom = std::sqrt(p_star_sq * recip_sq);
if (denom >= epsilon) {
float c = (p_star_x * recip_x + p_star_y * recip_y + p_star_z * recip_z) / denom;
c = std::fmax(-1.0f, std::fmin(1.0f, c));
delta_phi_deg = std::acos(c) * rad_to_deg;
}
}
}
// Inlined RecipToDector with rot1 and rot2 (rot3 = 0)
// Apply rotation matrix transpose
float S_rot_x = rot[0] * S_x + rot[1] * S_y + rot[2] * S_z;
@@ -96,7 +124,7 @@ int BraggPrediction::Calc(const DiffractionExperiment &experiment, const Crystal
.h = h,
.k = k,
.l = l,
.delta_phi_deg = NAN,
.delta_phi_deg = delta_phi_deg,
.predicted_x = x,
.predicted_y = y,
.d = d,