jfjoch_viewer: Resolution estimate plot uses 1/d^2 as Y-axis

viewer/JFJochViewerDatasetInfo.cpp

@@ -80,7 +80,7 @@ void JFJochViewerDatasetInfo::datasetLoaded(std::shared_ptr<const JFJochReaderDa
     if (dataset) {
        UpdatePlot();
     } else {
-        chart_view->loadValues<float>({}, 0);
+        chart_view->loadValues<float>({}, 0, false);
         grid_scan_image->clear();
     }
 }
@@ -127,7 +127,7 @@ void JFJochViewerDatasetInfo::UpdatePlot() {
         else if (val == 8)
             data = dataset->b_factor;
 
-        chart_view->loadValues(data, image_number);
+        chart_view->loadValues(data, image_number, val == 7);
         if (dataset->experiment.GetGridScan()) {
             stack->setCurrentWidget(grid_scan_image);
             grid_scan_image->loadData(data, dataset->experiment.GetGridScan().value());

viewer/charts/JFJochChartView.cpp

@@ -4,11 +4,12 @@
 #include <QMenu>
 #include <QApplication>
 #include <QClipboard>
+#include <QCategoryAxis>
 
 #include "JFJochChartView.h"
 
 JFJochChartView::JFJochChartView(QWidget *parent)
-: QChartView(new QChart(), parent) {
+    : QChartView(new QChart(), parent) {
     chart()->legend()->hide();
     setRenderHint(QPainter::Antialiasing);
     setRubberBand(QChartView::RubberBand::RectangleRubberBand);
@@ -17,7 +18,6 @@ JFJochChartView::JFJochChartView(QWidget *parent)
     m_hoverLoadTimer = new QTimer(this);
     m_hoverLoadTimer->setSingleShot(true);
     connect(m_hoverLoadTimer, &QTimer::timeout, this, &JFJochChartView::onHoverLoadTimeout);
-
 }
 
 void JFJochChartView::setImage(int64_t val) {
@@ -107,7 +107,7 @@ void JFJochChartView::updateChart() {
         chart()->createDefaultAxes();
 
         // Set Y-axis behavior according to options
-        QValueAxis *axisY = qobject_cast<QValueAxis*>(chart()->axisY(series));
+        QValueAxis *axisY = qobject_cast<QValueAxis *>(chart()->axisY(series));
         if (axisY) {
             if (std::isfinite(dispMin) && std::isfinite(dispMax)) {
                 if (m_minYZeroEnabled) {
@@ -123,6 +123,51 @@ void JFJochChartView::updateChart() {
                     axisY->setRange(dispMin, dispMax);
                 }
             }
+
+            // If Y is in 1/d^2, hide numeric labels and add a category axis with d labels
+            if (m_yOneOverD) {
+                axisY->setLabelsVisible(false); // keep grid/ticks from value axis
+
+                // Build a mirrored visible axis with labels in d (Å)
+                auto *axYcat = new QCategoryAxis();
+                axYcat->setLabelsPosition(QCategoryAxis::AxisLabelsPositionOnValue);
+                axYcat->setGridLineVisible(false);
+                axYcat->setMinorGridLineVisible(false);
+                axYcat->setTitleText(QStringLiteral("d (Å)"));
+
+                const int tickCountY = std::max(2, axisY->tickCount());
+                const double ymin = axisY->min();
+                const double ymax = axisY->max();
+                const double ystep = (tickCountY > 1) ? (ymax - ymin) / (tickCountY - 1) : 0.0;
+
+                for (int i = 0; i < tickCountY; ++i) {
+                    const double yv = (i == tickCountY - 1) ? ymax : (ymin + i * ystep);
+                    QString lab;
+                    if (!(yv > 0.0)) {
+                        lab = QStringLiteral("—"); // invalid for d
+                    } else if (std::abs(yv) < 1e-300) {
+                        lab = QStringLiteral("∞");
+                    } else {
+                        const double d = 1.0 / std::sqrt(yv);
+                        lab = QString("%1 Å").arg(d, 0, 'f', 2);
+                    }
+                    axYcat->append(lab, yv);
+                }
+                chart()->addAxis(axYcat, Qt::AlignLeft);
+                series->attachAxis(axYcat);
+                currentSeries->attachAxis(axYcat);
+
+                // Give a bit more room on the left so labels are not clipped
+                QMargins m = chart()->margins();
+                if (m.left() < 12) {
+                    m.setLeft(12);
+                    chart()->setMargins(m);
+                }
+            } else {
+                // Normal numeric labels
+                axisY->setTitleText(QString());
+                axisY->setLabelsVisible(true);
+            }
         }
     }
 }
@@ -192,9 +237,22 @@ void JFJochChartView::mouseMoveEvent(QMouseEvent *event) {
                                 ptOnChart.x(), plotArea.bottom()));
 
     // Status bar text
-    QString text = QString("image = %1, value = %2")
-            .arg(idx)
-            .arg(values[static_cast<size_t>(idx)], 0, 'g', 6);
+    const double yv = values[static_cast<size_t>(idx)];
+    QString text;
+    if (m_yOneOverD) {
+        if (std::isfinite(yv) && yv > 0.0) {
+            const double d = 1.0 / std::sqrt(yv);
+            text = QString("image = %1, d = %2 Å")
+                    .arg(idx)
+                    .arg(d, 0, 'f', 2);
+        } else {
+            text = QString("image = %1, no resolution estimate").arg(idx);
+        }
+    } else {
+        text = QString("image = %1, value = %2")
+                .arg(idx)
+                .arg(yv, 0, 'g', 6);
+    }
     emit writeStatusBar(text, 6000);
 
     // Debounced image load on hover when Shift is pressed

viewer/charts/JFJochChartView.h

@@ -25,6 +25,7 @@ class JFJochChartView : public QChartView {
     int64_t curr_image = 0;
 
     bool m_minYZeroEnabled = true;
+    bool m_yOneOverD = false;
 
     void updateChart();
 
@@ -51,10 +52,21 @@ public slots:
 
 public:
     template<class T>
-    void loadValues(const std::vector<T> &input, int64_t image) {
+    void loadValues(const std::vector<T> &input, int64_t image, bool one_over_d2) {
+        m_yOneOverD = one_over_d2;
+
         values.resize(input.size());
-        for (int i = 0; i < input.size(); i++)
-            values[i] = static_cast<float>(input[i]);
+        for (int i = 0; i < input.size(); i++) {
+            if (one_over_d2) {
+
+                float d = static_cast<float>(input[i]);
+                if (!std::isfinite(d))
+                    values[i] = 0.0f;
+                else
+                    values[i] = 1.0f / (d * d);
+            } else
+                values[i] = static_cast<float>(input[i]);
+        }
         curr_image = image;
         updateChart();
     }