viewer: show the space group in the merge-statistics window

The de-novo space-group search (SearchSpaceGroup) already ran inside Rugnux but
only its chosen number survived on ProcessResult, and the viewer dropped even
that. Carry the structured SearchSpaceGroupResult (point group + ranked
candidate scores) on ProcessResult and thread it into JFJochMergeStatsWindow,
which now shows a 'Space group' hero card (the final group, searched or fixed)
plus a compact table of candidate groups and their absence scores.

The library no longer renders the search to text (it used to embed it in
merge_statistics_text); rugnux_cli formats it for stdout instead, so the CLI
keeps its text table while the viewer draws a proper table and does not spew it
to stdout. Also surface a user-fixed space group on the result so the card
shows it too.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

rugnux/Rugnux.cpp

@@ -669,7 +669,6 @@ ProcessResult Rugnux::Run(RugnuxObserver *observer) {
             if (end_msg.rotation_lattice_type.has_value())
                 sg_opts.lattice_system = end_msg.rotation_lattice_type->crystal_system;
             auto sg_search = SearchSpaceGroup(sm.merged, sg_opts);
-            stats_text << SearchSpaceGroupResultToText(sg_search) << "\n\n";
 
             // Miller-index reindex under a change of basis: (h,k,l)_conv = reindex * (h,k,l)_prim.
             const auto reindex_hkl = [](auto &r, const gemmi::Mat33 &m) {
@@ -723,8 +722,6 @@ ProcessResult Rugnux::Run(RugnuxObserver *observer) {
                     SearchSpaceGroupOptions o2 = sg_opts;
                     o2.lattice_system = cand.system;
                     const auto s2 = SearchSpaceGroup(merged_c, o2);
-                    stats_text << "Pseudo-symmetry re-test in the metric candidate's conventional setting:\n"
-                               << SearchSpaceGroupResultToText(s2) << "\n\n";
                     if (s2.best_space_group.has_value() && s2.best_space_group->number > 1) {
                         // The centring cannot be confirmed from absences here (integrated in the primitive
                         // cell, so the centring-absent reflections do not exist) - it is metric-determined.
@@ -785,6 +782,10 @@ ProcessResult Rugnux::Run(RugnuxObserver *observer) {
                 phase("Re-scaling in space group " + sg.short_name());
                 sm = scale_and_merge(sg.short_name(), false);
             }
+            result.space_group_search = sg_search;
+        } else {
+            // A space group was fixed by the user; surface it so the viewer/CLI can still show it.
+            result.space_group_number = experiment_.GetSpaceGroupNumber();
         }
 
         // Ice-ring CC1/2 mask: a hexagonal-ice ring whose merged half-set CC1/2 collapses well below its

rugnux/Rugnux.h

@@ -17,6 +17,7 @@
 #include "../image_analysis/spot_finding/SpotFindingSettings.h"
 #include "../image_analysis/scale_merge/Merge.h"   // MergeStatistics
 #include "../image_analysis/scale_merge/TwinningAnalysis.h"   // TwinningAnalysisResult
+#include "../image_analysis/scale_merge/SearchSpaceGroup.h"   // SearchSpaceGroupResult
 
 class JFJochHDF5Reader;
 
@@ -93,9 +94,14 @@ struct ProcessResult {
     // Twinning analysis of the final merged intensities (l_test_pairs == 0 when not computed).
     TwinningAnalysisResult twinning;
 
-    // Space group determined by the search (when the user did not fix one), used for the final
-    // re-scale/merge and written to the master file.
+    // Space group used for the final re-scale/merge and written to the master file: determined by the
+    // search when the user did not fix one, otherwise the fixed group.
     std::optional<int64_t> space_group_number;
+
+    // Structured result of the de-novo space-group search (point group + ranked candidate scores),
+    // populated only when a search ran (no space group was fixed). The library no longer renders it to
+    // text - the CLI formats it for stdout, the viewer draws it as a table.
+    std::optional<SearchSpaceGroupResult> space_group_search;
 };
 
 // Callbacks for progress and live results. Methods may be called from worker threads, so an

tools/rugnux_cli.cpp

@@ -27,6 +27,7 @@
 #include "../image_analysis/scale_merge/RotationScaleMerge.h"
 #include "../image_analysis/scale_merge/ResolutionCutoff.h"
 #include "../image_analysis/scale_merge/TwinningAnalysis.h"
+#include "../image_analysis/scale_merge/SearchSpaceGroup.h"
 #include "../rugnux/Rugnux.h"
 
 // Default rot3d per-frame scale-G smoothing range (XDS DELPHI-like), in degrees of rotation.
@@ -1291,6 +1292,11 @@ int main(int argc, char **argv) {
     }
     g_active_process = nullptr;
 
+    // The space-group search is rendered here (not in the library) so the viewer does not emit it on
+    // stdout and the CLI owns the format.
+    if (result.space_group_search.has_value())
+        std::cout << std::endl << SearchSpaceGroupResultToText(*result.space_group_search) << std::endl;
+
     if (!result.merge_statistics_text.empty())
         std::cout << std::endl << result.merge_statistics_text << std::endl;
 

viewer/windows/JFJochMergeStatsWindow.cpp

@@ -12,12 +12,15 @@
 #include <QHeaderView>
 #include <QLabel>
 #include <QStackedWidget>
+#include <QStringList>
 #include <QTableWidget>
 #include <QToolButton>
 #include <QVBoxLayout>
 #include <QtCharts/QChart>
 #include <QtCharts/QValueAxis>
 
+#include "gemmi/symmetry.hpp"   // find_spacegroup_by_number
+
 #include "../charts/JFJochSimpleChartView.h"
 #include "../widgets/ToolbarIcons.h"
 
@@ -62,7 +65,10 @@ namespace {
 
 JFJochMergeStatsWindow::JFJochMergeStatsWindow(const QString &title, const MergeStatistics &stats,
                                                double isa, bool has_reference,
-                                               const TwinningAnalysisResult &twinning, QWidget *parent)
+                                               const TwinningAnalysisResult &twinning,
+                                               std::optional<int64_t> space_group_number,
+                                               const std::optional<SearchSpaceGroupResult> &space_group_search,
+                                               QWidget *parent)
     : QWidget(parent, Qt::Window), stats_(stats), has_reference_(has_reference) {
     setWindowTitle("Merge statistics — " + title);
     setAttribute(Qt::WA_DeleteOnClose);
@@ -87,8 +93,57 @@ JFJochMergeStatsWindow::JFJochMergeStatsWindow(const QString &title, const Merge
     hero->addWidget(MakeCard(num(multiplicity, 1), "Multiplicity", this));
     if (has_reference_)
         hero->addWidget(MakeCard(pct(o.cc_ref * 100.0), "CCref", this));
+    if (space_group_number.has_value()) {
+        const gemmi::SpaceGroup *sg = gemmi::find_spacegroup_by_number(static_cast<int>(*space_group_number));
+        const QString sg_name = sg ? QString::fromStdString(sg->short_name())
+                                   : QString::number(*space_group_number);
+        hero->addWidget(MakeCard(sg_name, "Space group", this));
+    }
     layout->addLayout(hero);
 
+    // De-novo space-group search: the point group + the ranked candidates it scored (only present when
+    // the space group was not fixed by the user). A summary line above a compact table.
+    if (space_group_search.has_value() && !space_group_search->candidates.empty()) {
+        const auto &sgs = *space_group_search;
+        QString summary = "Point group " + QString::fromStdString(sgs.point_group_hm.empty() ? "?" : sgs.point_group_hm);
+        if (!sgs.alternatives.empty()) {
+            QStringList alts;
+            for (const auto &alt : sgs.alternatives)
+                alts << QString::fromStdString(alt.short_name());
+            summary += "  ·  indistinguishable from these data: " + alts.join(", ");
+        }
+        auto *sgLabel = new QLabel(summary, this);
+        sgLabel->setStyleSheet("color: gray;");
+        layout->addWidget(sgLabel);
+
+        auto *sgTable = new QTableWidget(this);
+        sgTable->setEditTriggers(QAbstractItemView::NoEditTriggers);
+        sgTable->verticalHeader()->setVisible(false);
+        const QStringList sgHeaders{"Space group", "Absent", "Viol.", "⟨I/σ⟩ abs", "⟨I/σ⟩ pres", "Consistent"};
+        sgTable->setColumnCount(sgHeaders.size());
+        sgTable->setHorizontalHeaderLabels(sgHeaders);
+        sgTable->setRowCount(static_cast<int>(sgs.candidates.size()));
+        for (int i = 0; i < static_cast<int>(sgs.candidates.size()); ++i) {
+            const auto &c = sgs.candidates[i];
+            int col = 0;
+            auto set = [&](const QString &t, bool leftAlign = false) {
+                auto *it = new QTableWidgetItem(t);
+                it->setTextAlignment((leftAlign ? Qt::AlignLeft : Qt::AlignRight) | Qt::AlignVCenter);
+                if (c.selected) { QFont f = it->font(); f.setBold(true); it->setFont(f); }
+                sgTable->setItem(i, col++, it);
+            };
+            set(QString::fromStdString(c.space_group.short_name()) + (c.selected ? " *" : ""), true);
+            set(QString::number(c.absent_observed));
+            set(QString::number(c.absent_violations));
+            set(QString::number(c.absent_mean_i_over_sigma, 'f', 2));
+            set(QString::number(c.present_mean_i_over_sigma, 'f', 2));
+            set(c.consistent ? QStringLiteral("yes") : QStringLiteral("no"));
+        }
+        sgTable->horizontalHeader()->setSectionResizeMode(QHeaderView::Stretch);
+        sgTable->setMaximumHeight(160);   // a secondary detail — keep the shells plot the focus
+        layout->addWidget(sgTable);
+    }
+
     // --- Twinning test (Padilla-Yeates L-test + second moment) ---
     // A red-outlined banner flags suspected twinning; otherwise a quiet grey "all clear".
     if (twinning.l_test_pairs > 0) {

viewer/windows/JFJochMergeStatsWindow.h

@@ -5,8 +5,12 @@
 
 #include <QWidget>
 
+#include <cstdint>
+#include <optional>
+
 #include "../../image_analysis/scale_merge/Merge.h"   // MergeStatistics
 #include "../../image_analysis/scale_merge/TwinningAnalysis.h"   // TwinningAnalysisResult
+#include "../../image_analysis/scale_merge/SearchSpaceGroup.h"   // SearchSpaceGroupResult
 
 class QComboBox;
 class QLabel;
@@ -23,7 +27,10 @@ class JFJochMergeStatsWindow : public QWidget {
 public:
     JFJochMergeStatsWindow(const QString &title, const MergeStatistics &stats,
                            double isa, bool has_reference,
-                           const TwinningAnalysisResult &twinning, QWidget *parent = nullptr);
+                           const TwinningAnalysisResult &twinning,
+                           std::optional<int64_t> space_group_number,
+                           const std::optional<SearchSpaceGroupResult> &space_group_search,
+                           QWidget *parent = nullptr);
 
 private:
     MergeStatistics stats_;

viewer/windows/JFJochProcessingJobsWindow.cpp

@@ -364,7 +364,8 @@ void JFJochProcessingJobsWindow::showStats(const QString &id) {
     for (const auto &j: jobs_) {
         if (j.id == id && j.has_merge_stats) {
             auto *win = new JFJochMergeStatsWindow(j.label, j.merge_stats, j.isa, j.merge_has_reference,
-                                                   j.twinning, window());
+                                                   j.twinning, j.space_group_number, j.space_group_search,
+                                                   window());
             win->show();
             return;
         }
@@ -518,6 +519,8 @@ void JFJochProcessingJobsWindow::onFinished(ProcessResult result) {
         jobs_[row].isa = result.error_model_isa;
         jobs_[row].merge_has_reference = result.has_reference;
         jobs_[row].twinning = result.twinning;
+        jobs_[row].space_group_number = result.space_group_number;
+        jobs_[row].space_group_search = result.space_group_search;
         if (jobs_[row].graph_btn)
             jobs_[row].graph_btn->setEnabled(true);
         showStats(jobs_[row].id);

viewer/windows/JFJochProcessingJobsWindow.h

@@ -6,6 +6,8 @@
 #include <QElapsedTimer>
 #include <QString>
 #include <QWidget>
+#include <cstdint>
+#include <optional>
 #include <vector>
 
 #include "../JFJochProcessController.h"
@@ -64,6 +66,8 @@ private:
         double isa = 0.0;
         bool merge_has_reference = false;
         TwinningAnalysisResult twinning;    // twinning test of the merged intensities
+        std::optional<int64_t> space_group_number;                  // final space group (searched or fixed)
+        std::optional<SearchSpaceGroupResult> space_group_search;   // ranked candidates, when a search ran
         QToolButton *graph_btn = nullptr;   // per-row "show statistics" button (enabled once stats exist)
     };
     struct JobSpec {