From d77215aecb197ac72e040fad904cfc407f50fd25 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20K=C3=A4berich?= <j.kaeberich@gmx.de>
Date: Fri, 31 Oct 2025 15:42:42 +0100
Subject: [PATCH] initialize new plots with the correct span

---
 .../LibreVNA-GUI/SpectrumAnalyzer/spectrumanalyzer.cpp   | 2 +-
 .../PC_Application/LibreVNA-GUI/Traces/tracemodel.cpp    | 9 +++++++++
 Software/PC_Application/LibreVNA-GUI/Traces/tracemodel.h | 6 ++++++
 .../PC_Application/LibreVNA-GUI/Traces/traceplot.cpp     | 3 +--
 .../PC_Application/LibreVNA-GUI/Traces/tracexyplot.cpp   | 3 +--
 Software/PC_Application/LibreVNA-GUI/VNA/vna.cpp         | 2 +-
 6 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/Software/PC_Application/LibreVNA-GUI/SpectrumAnalyzer/spectrumanalyzer.cpp b/Software/PC_Application/LibreVNA-GUI/SpectrumAnalyzer/spectrumanalyzer.cpp
index 6f28d66..9deb7b4 100644
--- a/Software/PC_Application/LibreVNA-GUI/SpectrumAnalyzer/spectrumanalyzer.cpp
+++ b/Software/PC_Application/LibreVNA-GUI/SpectrumAnalyzer/spectrumanalyzer.cpp
@@ -914,7 +914,7 @@ void SpectrumAnalyzer::ConfigureDevice()
         average.reset(DeviceDriver::SApoints());
         UpdateAverageCount();
         traceModel.clearLiveData();
-        emit traceModel.SpanChanged(settings.freqStart, settings.freqStop);
+        traceModel.setSpan(settings.freqStart, settings.freqStop);
     } else {
         if(window->getDevice()) {
             changingSettings = true;
diff --git a/Software/PC_Application/LibreVNA-GUI/Traces/tracemodel.cpp b/Software/PC_Application/LibreVNA-GUI/Traces/tracemodel.cpp
index e69e900..02646ef 100644
--- a/Software/PC_Application/LibreVNA-GUI/Traces/tracemodel.cpp
+++ b/Software/PC_Application/LibreVNA-GUI/Traces/tracemodel.cpp
@@ -9,6 +9,8 @@ using namespace std;
 TraceModel::TraceModel(QObject *parent)
     : QAbstractTableModel(parent)
 {
+    spanFmin = 0.0;
+    spanFmax = 6000000000.0;
     traces.clear();
     source = DataSource::Unknown;
     lastSweepPosition = 0.0;
@@ -368,6 +370,13 @@ double TraceModel::getSweepPosition() const
     }
 }
 
+void TraceModel::setSpan(double fmin, double fmax)
+{
+    spanFmin = fmin;
+    spanFmax = fmax;
+    emit SpanChanged(fmin, fmax);
+}
+
 MarkerModel *TraceModel::getMarkerModel() const
 {
     return markerModel;
diff --git a/Software/PC_Application/LibreVNA-GUI/Traces/tracemodel.h b/Software/PC_Application/LibreVNA-GUI/Traces/tracemodel.h
index e8f32fc..4fa5edb 100644
--- a/Software/PC_Application/LibreVNA-GUI/Traces/tracemodel.h
+++ b/Software/PC_Application/LibreVNA-GUI/Traces/tracemodel.h
@@ -62,6 +62,10 @@ public:
 
     double getSweepPosition() const;
 
+    void setSpan(double fmin, double fmax);
+    double getSpanStart() {return spanFmin;}
+    double getSpanStop() {return spanFmax;}
+
 signals:
     void SpanChanged(double fmin, double fmax);
     void traceAdded(Trace *t);
@@ -80,6 +84,8 @@ private:
     QDateTime lastReceivedData;
     std::vector<Trace*> traces;
     MarkerModel *markerModel;
+
+    double spanFmin, spanFmax;
 };
 
 #endif // TRACEMODEL_H
diff --git a/Software/PC_Application/LibreVNA-GUI/Traces/traceplot.cpp b/Software/PC_Application/LibreVNA-GUI/Traces/traceplot.cpp
index 931032d..fc461b3 100644
--- a/Software/PC_Application/LibreVNA-GUI/Traces/traceplot.cpp
+++ b/Software/PC_Application/LibreVNA-GUI/Traces/traceplot.cpp
@@ -42,8 +42,7 @@ TracePlot::TracePlot(TraceModel &model, QWidget *parent)
     lastUpdate = QTime::currentTime();
     replotTimer.setSingleShot(true);
     connect(&replotTimer, &QTimer::timeout, this, qOverload<>(&TracePlot::update));
-    sweep_fmin = std::numeric_limits<double>::lowest();
-    sweep_fmax = std::numeric_limits<double>::max();
+    TracePlot::updateSpan(model.getSpanStart(), model.getSpanStop());
     xSweep = std::numeric_limits<double>::quiet_NaN();
     // get notified when the span changes
     connect(&model, &TraceModel::SpanChanged, this, qOverload<double, double>(&TracePlot::updateSpan));
diff --git a/Software/PC_Application/LibreVNA-GUI/Traces/tracexyplot.cpp b/Software/PC_Application/LibreVNA-GUI/Traces/tracexyplot.cpp
index 3fcd8ea..3547eea 100644
--- a/Software/PC_Application/LibreVNA-GUI/Traces/tracexyplot.cpp
+++ b/Software/PC_Application/LibreVNA-GUI/Traces/tracexyplot.cpp
@@ -29,8 +29,7 @@ TraceXYPlot::TraceXYPlot(TraceModel &model, QWidget *parent)
     // Setup default axis
     setYAxis(0, YAxis::Type::Magnitude, false, false, YAxis::getDefaultLimitMin(YAxis::Type::Magnitude), YAxis::getDefaultLimitMax(YAxis::Type::Magnitude), 14, true);
     setYAxis(1, YAxis::Type::Phase, false, false, YAxis::getDefaultLimitMin(YAxis::Type::Phase), YAxis::getDefaultLimitMax(YAxis::Type::Phase), 12, true);
-    // enable autoscaling and set for full span (no information about actual span available yet)
-    updateSpan(0, 6000000000);
+
     setXAxis(XAxis::Type::Frequency, XAxisMode::UseSpan, false, 0, 6000000000, 10, true);
     initializeTraceInfo();
 }
diff --git a/Software/PC_Application/LibreVNA-GUI/VNA/vna.cpp b/Software/PC_Application/LibreVNA-GUI/VNA/vna.cpp
index e418b30..b87379e 100644
--- a/Software/PC_Application/LibreVNA-GUI/VNA/vna.cpp
+++ b/Software/PC_Application/LibreVNA-GUI/VNA/vna.cpp
@@ -1961,7 +1961,7 @@ void VNA::ConfigureDevice(bool resetTraces, std::function<void(bool)> cb)
         double start = settings.sweepType == SweepType::Frequency ? settings.Freq.start : settings.Power.start;
         double stop = settings.sweepType == SweepType::Frequency ? settings.Freq.stop : settings.Power.stop;
         int npoints = settings.npoints;
-        emit traceModel.SpanChanged(start, stop);
+        traceModel.setSpan(start, stop);
         if (settings.segments > 1) {
             // more than one segment, adjust start/stop
             npoints = ceil((double) settings.npoints / settings.segments);