From cf31fd7908c794c7842c5cca3268ed380d5645f3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20K=C3=A4berich?= <j.kaeberich@gmx.de>
Date: Mon, 11 Jul 2022 21:37:06 +0200
Subject: [PATCH] Basic working support for math operations between traces

---
 .../Calibration/calibration.cpp               |   4 +-
 .../PC_Application/Traces/Marker/marker.cpp   |   2 +-
 Software/PC_Application/Traces/trace.cpp      | 399 ++++++++++++++++--
 Software/PC_Application/Traces/trace.h        |  75 +++-
 .../PC_Application/Traces/traceeditdialog.cpp | 100 ++++-
 .../PC_Application/Traces/traceeditdialog.ui  |  44 +-
 Software/PC_Application/Traces/tracemodel.cpp |  17 +-
 .../PC_Application/Traces/tracewidget.cpp     |   2 +
 8 files changed, 579 insertions(+), 64 deletions(-)

diff --git a/Software/PC_Application/Calibration/calibration.cpp b/Software/PC_Application/Calibration/calibration.cpp
index 96d5b95..1645447 100644
--- a/Software/PC_Application/Calibration/calibration.cpp
+++ b/Software/PC_Application/Calibration/calibration.cpp
@@ -672,7 +672,7 @@ std::vector<Trace *> Calibration::getErrorTermTraces()
     constexpr bool reflection[12] = {true, true, false, false, true, false, true, true, false, false, true, false};
     for(int i=0;i<12;i++) {
         auto t = new Trace(traceNames[i], Qt::red);
-        t->setCalibration(true);
+        t->setCalibration();
         t->setReflection(reflection[i]);
         traces.push_back(t);
     }
@@ -728,7 +728,7 @@ std::vector<Trace *> Calibration::getMeasurementTraces()
             }
             for(auto prefix : usedPrefixes) {
                 auto t = new Trace(prefix + " " + info.name);
-                t->setCalibration(true);
+                t->setCalibration();
                 t->setReflection(prefix == "S11" || prefix == "S22");
                 for(auto p : m.second.datapoints) {
                     Trace::Data d;
diff --git a/Software/PC_Application/Traces/Marker/marker.cpp b/Software/PC_Application/Traces/Marker/marker.cpp
index 7e8e970..055960a 100644
--- a/Software/PC_Application/Traces/Marker/marker.cpp
+++ b/Software/PC_Application/Traces/Marker/marker.cpp
@@ -870,7 +870,7 @@ std::set<Marker::Type> Marker::getSupportedTypes()
                 supported.insert(Type::Highpass);
                 supported.insert(Type::Bandpass);
             }
-            if(parentTrace->isLive()) {
+            if(parentTrace->getSource() == Trace::Source::Live) {
                 switch(parentTrace->liveParameter()) {
                 case Trace::LiveParameter::S11:
                 case Trace::LiveParameter::S12:
diff --git a/Software/PC_Application/Traces/trace.cpp b/Software/PC_Application/Traces/trace.cpp
index dbb38b7..3515876 100644
--- a/Software/PC_Application/Traces/trace.cpp
+++ b/Software/PC_Application/Traces/trace.cpp
@@ -4,6 +4,8 @@
 #include "Util/util.h"
 #include "Marker/marker.h"
 #include "traceaxis.h"
+#include "tracemodel.h"
+#include "Math/parser/mpParser.h"
 
 #include <math.h>
 #include <QDebug>
@@ -12,19 +14,23 @@
 #include <functional>
 
 using namespace std;
+using namespace mup;
 
 Trace::Trace(QString name, QColor color, LiveParameter live)
-    : _name(name),
+    : model(nullptr),
+      _name(name),
       _color(color),
+      source(Source::Live),
+      hash(0),
+      hashSet(false),
+      JSONskipHash(false),
       _liveType(LivedataType::Overwrite),
       _liveParam(live),
       vFactor(0.66),
       reflection(true),
-      reference_impedance(50.0),
       visible(true),
       paused(false),
-      createdFromFile(false),
-      calibration(false),
+      reference_impedance(50.0),
       domain(DataType::Frequency),
       lastMath(nullptr)
 {
@@ -32,6 +38,10 @@ Trace::Trace(QString name, QColor color, LiveParameter live)
     mathOps.push_back(self);
     updateLastMath(mathOps.rbegin());
 
+    lastMathUpdate = QTime::currentTime();
+    mathCalcTimer.setSingleShot(true);
+    connect(&mathCalcTimer, &QTimer::timeout, this, &Trace::calculateMath);
+
     self.enabled = false;
     dataType = DataType::Frequency;
     connect(this, &Trace::typeChanged, [=](){
@@ -52,8 +62,8 @@ Trace::~Trace()
     emit deleted(this);
 }
 
-void Trace::clear() {
-    if(paused) {
+void Trace::clear(bool force) {
+    if(paused && !force) {
         return;
     }
     data.clear();
@@ -166,7 +176,8 @@ void Trace::fillFromTouchstone(Touchstone &t, unsigned int parameter)
             break;
         }
     }
-    createdFromFile = true;
+    clearMathSources();
+    source = Source::File;
     reference_impedance = t.getReferenceImpedance();
     emit typeChanged(this);
     emit outputSamplesChanged(0, data.size());
@@ -241,7 +252,8 @@ QString Trace::fillFromCSV(CSV &csv, unsigned int parameter)
         addData(d, domain);
     }
     reflection = false;
-    createdFromFile = true;
+    clearMathSources();
+    source = Source::File;
     emit typeChanged(this);
     emit outputSamplesChanged(0, data.size());
     return lastTraceName;
@@ -269,7 +281,8 @@ void Trace::fillFromDatapoints(Trace &S11, Trace &S12, Trace &S21, Trace &S22, c
 
 void Trace::fromLivedata(Trace::LivedataType type, LiveParameter param)
 {
-    createdFromFile = false;
+    clearMathSources();
+    source = Source::Live;
     _liveType = type;
     _liveParam = param;
     if(param == LiveParameter::S11 || param == LiveParameter::S22) {
@@ -280,6 +293,15 @@ void Trace::fromLivedata(Trace::LivedataType type, LiveParameter param)
     emit typeChanged(this);
 }
 
+void Trace::fromMath()
+{
+    source = Source::Math;
+    clear();
+    updateMathTracePoints();
+    scheduleMathCalculation(0, data.size());
+    emit typeChanged(this);
+}
+
 void Trace::setColor(QColor color) {
     if(_color != color) {
         _color = color;
@@ -309,6 +331,281 @@ void Trace::markerVisibilityChanged(Marker *m)
     emit visibilityChanged(this);
 }
 
+const QString &Trace::getMathFormula() const
+{
+    return mathFormula;
+}
+
+void Trace::setMathFormula(const QString &newMathFormula)
+{
+    mathFormula = newMathFormula;
+}
+
+bool Trace::mathFormularValid() const
+{
+    if(mathFormula.isEmpty()) {
+        return false;
+    }
+    try {
+        ParserX parser(pckCOMMON | pckUNIT | pckCOMPLEX);
+        parser.SetExpr(mathFormula.toStdString());
+        auto vars = parser.GetExprVar();
+        for(auto var : vars) {
+            auto varName = QString::fromStdString(var.first);
+            // try to find variable name
+            bool found = false;
+            for(auto ms : mathSourceTraces) {
+                if(ms.second == varName) {
+                    found = true;
+                    break;
+                }
+            }
+            if(!found) {
+                return false;
+            }
+        }
+    } catch (const ParserError &e) {
+        // parser error occurred
+        return false;
+    }
+    // all variables used in the expression are set as math sources
+    return true;
+}
+
+bool Trace::resolveMathSourceHashes()
+{
+    bool success = true;
+    for(auto unresolved : mathSourceUnresolvedHashes) {
+        if(!addMathSource(unresolved.first, unresolved.second)) {
+            success = false;
+        }
+    }
+    if(success) {
+        mathSourceUnresolvedHashes.clear();
+    }
+    return success;
+}
+
+bool Trace::updateMathTracePoints()
+{
+    if(!mathSourceTraces.size()) {
+        return false;
+    }
+    double startX = std::numeric_limits<double>::lowest();
+    double stopX = std::numeric_limits<double>::max();
+    double stepSize = std::numeric_limits<double>::max();
+    for(auto t : mathSourceTraces) {
+        if(t.first->minX() > startX) {
+            startX = t.first->minX();
+        }
+        if(t.first->maxX() < stopX) {
+            stopX = t.first->maxX();
+        }
+        double traceStepSize = std::numeric_limits<double>::max();
+        if(t.first->numSamples() > 1) {
+            traceStepSize = (t.first->maxX() - t.first->minX()) / (t.first->numSamples() - 1);
+        }
+        if(traceStepSize < stepSize) {
+            stepSize = traceStepSize;
+        }
+    }
+    unsigned int samples = round((stopX - startX) / stepSize + 1);
+    bool fullUpdate = false;
+    if(samples != data.size()) {
+        data.resize(samples);
+        fullUpdate = true;
+    }
+    if(samples > 0 && (startX != data.front().x || stopX != data.back().x)) {
+        fullUpdate = true;
+    }
+    if(fullUpdate) {
+        // steps changed, complete update required
+        mathUpdateBegin = 0;
+        mathUpdateEnd = samples;
+        for(unsigned int i=0;i<samples;i++) {
+            data[i].x = startX + i * stepSize;
+            data[i].y = numeric_limits<complex<double>>::quiet_NaN();
+        }
+        return true;
+    } else {
+        return false;
+    }
+}
+
+void Trace::mathSourceTraceDeleted(Trace *t)
+{
+    if (mathSourceTraces.count(t)) {
+        removeMathSource(t);
+    }
+}
+
+void Trace::scheduleMathCalculation(unsigned int begin, unsigned int end)
+{
+    if(source != Source::Math) {
+        return;
+    }
+    if(begin < mathUpdateBegin) {
+        mathUpdateBegin = begin;
+    }
+    if(end > mathUpdateEnd) {
+        mathUpdateEnd = end;
+    }
+    auto now = QTime::currentTime();
+    if (lastMathUpdate.msecsTo(now) >= MinMathUpdateInterval) {
+        calculateMath();
+    } else {
+        mathCalcTimer.start(MinMathUpdateInterval);
+    }
+}
+
+void Trace::calculateMath()
+{
+    lastMathUpdate = QTime::currentTime();
+    if(mathUpdateBegin >= data.size() || mathUpdateEnd >= data.size() + 1) {
+        return;
+    }
+    if(mathFormula.isEmpty()) {
+        error("Expression is empty");
+        return;
+    }
+    if(!isPaused()) {
+        try {
+            ParserX parser(pckCOMMON | pckUNIT | pckCOMPLEX);
+            parser.SetExpr(mathFormula.toStdString());
+            map<Trace*,Value> values;
+            Value x;
+            parser.DefineVar("x", Variable(&x));
+            for(const auto &ts : mathSourceTraces) {
+                values[ts.first] = Value();
+                parser.DefineVar(ts.second.toStdString(), Variable(&values[ts.first]));
+            }
+            for(unsigned int i=mathUpdateBegin;i<mathUpdateEnd;i++) {
+                x = data[i].x;
+                for(auto &val : values) {
+                    val.second = val.first->interpolatedSample(data[i].x).y;
+                }
+                Value res = parser.Eval();
+                data[i].y = res.GetComplex();
+            }
+        } catch (const ParserError &e) {
+            error(QString::fromStdString(e.GetMsg()));
+            // parser error occurred
+            for(unsigned int i=mathUpdateBegin;i<mathUpdateEnd;i++) {
+                data[i].y = numeric_limits<complex<double>>::quiet_NaN();
+            }
+        }
+        success();
+        emit outputSamplesChanged(mathUpdateBegin, mathUpdateEnd + 1);
+    }
+    mathUpdateBegin = data.size();
+    mathUpdateEnd = 0;
+}
+
+void Trace::clearMathSources()
+{
+    while(mathSourceTraces.size() > 0) {
+        removeMathSource(mathSourceTraces.begin()->first);
+    }
+}
+
+bool Trace::addMathSource(unsigned int hash, QString variableName)
+{
+    if(!model) {
+        return false;
+    }
+    for(auto t : model->getTraces()) {
+        if(t->toHash() == hash) {
+            return addMathSource(t, variableName);
+        }
+    }
+    return false;
+}
+
+bool Trace::mathDependsOn(Trace *t, bool onlyDirectDependency)
+{
+    if(mathSourceTraces.count(t)) {
+        return true;
+    }
+    if(onlyDirectDependency) {
+        return false;
+    } else {
+        // also check math source traces recursively
+        for(auto m : mathSourceTraces) {
+            if(m.first->mathDependsOn(t)) {
+                return true;
+            }
+        }
+        return false;
+    }
+}
+
+bool Trace::canAddAsMathSource(Trace *t)
+{
+    if(t == this) {
+        // can't add itself
+        return false;
+    }
+    // check if we would create a loop of math traces depending on each other
+    if(t->mathDependsOn(this)) {
+        return false;
+    }
+    if(mathSourceTraces.size() == 0) {
+        // no traces used as source yet, can add anything
+        return true;
+    } else {
+        // can only add traces of the same domain
+        if(mathSourceTraces.begin()->first->outputType() == t->outputType()) {
+            return true;
+        } else {
+            return false;
+        }
+    }
+}
+
+bool Trace::addMathSource(Trace *t, QString variableName)
+{
+//    qDebug() << "Adding trace" << t << "as a math source to" << this << "as variable" << variableName;
+    if(!canAddAsMathSource(t)) {
+        return false;
+    }
+    mathSourceTraces[t] = variableName;
+    connect(t, &Trace::deleted, this, &Trace::mathSourceTraceDeleted, Qt::UniqueConnection);
+    connect(t, &Trace::dataChanged, this, [=](unsigned int begin, unsigned int end){
+        updateMathTracePoints();
+        auto startX = t->sample(begin).x;
+        auto stopX = t->sample(end).x;
+        scheduleMathCalculation(index(startX), index(stopX));
+    });
+    return true;
+}
+
+void Trace::removeMathSource(Trace *t)
+{
+//    qDebug() << "Removing trace" << t << "as a math source from" << this;
+    mathSourceTraces.erase(t);
+    disconnect(t, &Trace::deleted, this, &Trace::mathSourceTraceDeleted);
+    disconnect(t, &Trace::dataChanged, this, nullptr);
+}
+
+QString Trace::getSourceVariableName(Trace *t)
+{
+    if(mathSourceTraces.count(t)) {
+        return mathSourceTraces[t];
+    } else {
+        return QString();
+    }
+}
+
+TraceModel *Trace::getModel() const
+{
+    return model;
+}
+
+void Trace::setModel(TraceModel *model)
+{
+    this->model = model;
+}
+
 double Trace::getReferenceImpedance() const
 {
     return reference_impedance;
@@ -347,22 +644,41 @@ double Trace::distanceToTime(double distance)
 nlohmann::json Trace::toJSON()
 {
     nlohmann::json j;
-    if(isCalibration()) {
+    if(!JSONskipHash) {
+        j["hash"] = toHash(true);
+    }
+    if(source == Source::Calibration) {
         // calibration traces can't be saved
         return j;
     }
     j["name"] = _name.toStdString();
     j["color"] = _color.name().toStdString();
     j["visible"] = visible;
-    if(isLive()) {
+    switch(source) {
+    case Source::Live:
         j["type"] = "Live";
         j["parameter"] = _liveParam;
         j["livetype"] = _liveType;
         j["paused"] = paused;
-    } else if(isFromFile()) {
+        break;
+    case Source::File:
         j["type"] = "File";
         j["filename"] = filename.toStdString();
         j["parameter"] = fileParameter;
+        break;
+    case Source::Math: {
+        j["type"] = "Math";
+        j["expression"] = mathFormula.toStdString();
+        nlohmann::json jsources;
+        for(auto ms : mathSourceTraces) {
+            nlohmann::json jsource;
+            jsource["trace"] = ms.first->toHash();
+            jsource["variable"] = ms.second.toStdString();
+            jsources.push_back(jsource);
+        }
+        j["sources"] = jsources;
+    }
+        break;
     }
     j["velocityFactor"] = vFactor;
     j["reflection"] = reflection;
@@ -388,8 +704,13 @@ nlohmann::json Trace::toJSON()
 
 void Trace::fromJSON(nlohmann::json j)
 {
-    createdFromFile = false;
-    calibration = false;
+    source = Source::Live;
+    if(j.contains("hash")) {
+        hash = j["hash"];
+        hashSet = true;
+    } else {
+        hashSet = false;
+    }
     _name = QString::fromStdString(j.value("name", "Missing name"));
     _color = QColor(QString::fromStdString(j.value("color", "yellow")));
     visible = j.value("visible", true);
@@ -414,6 +735,19 @@ void Trace::fromJSON(nlohmann::json j)
             std::string what = e.what();
             throw runtime_error("Failed to create from file:" + what);
         }
+    } else if(type == "Math") {
+        mathFormula = QString::fromStdString(j.value("expression", ""));
+        if(j.contains("sources")) {
+            for(auto js : j["sources"]) {
+                auto hash = js.value("trace", 0);
+                QString varName = QString::fromStdString(js.value("variable", ""));
+                if(!addMathSource(hash, varName)) {
+                    qWarning() << "Unable to find requested math source trace ( hash:"<<hash<<"), probably not loaded yet";
+                    mathSourceUnresolvedHashes[hash] = varName;
+                }
+            }
+        }
+        fromMath();
     }
     vFactor = j.value("velocityFactor", 0.66);
     reflection = j.value("reflection", false);
@@ -453,12 +787,18 @@ void Trace::fromJSON(nlohmann::json j)
     enableMath(j.value("math_enabled", true));
 }
 
-unsigned int Trace::toHash()
+unsigned int Trace::toHash(bool forceUpdate)
 {
-    // taking the easy way: create the json string and hash it (already contains all necessary information)
-    // This is slower than it could be, but this function is only used when loading setups, so this isn't a big problem
-    std::string json_string = toJSON().dump();
-    return hash<std::string>{}(json_string);
+    if(!hashSet || forceUpdate) {
+        // taking the easy way: create the json string and hash it (already contains all necessary information)
+        // This is slower than it could be, but this function is only used when loading setups, so this isn't a big problem
+        JSONskipHash = true;
+        std::string json_string = toJSON().dump();
+        JSONskipHash = false;
+        hash = std::hash<std::string>{}(json_string);
+        hashSet = true;
+    }
+    return hash;
 }
 
 std::vector<Trace *> Trace::createFromTouchstone(Touchstone &t)
@@ -687,9 +1027,9 @@ QString Trace::description()
     return name() + ": measured data";
 }
 
-void Trace::setCalibration(bool value)
+void Trace::setCalibration()
 {
-    calibration = value;
+    source = Source::Calibration;
 }
 
 std::set<Marker *> Trace::getMarkers() const
@@ -731,21 +1071,6 @@ bool Trace::isPaused()
     return paused;
 }
 
-bool Trace::isFromFile()
-{
-    return createdFromFile;
-}
-
-bool Trace::isCalibration()
-{
-    return calibration;
-}
-
-bool Trace::isLive()
-{
-    return !isCalibration() && !isFromFile();
-}
-
 bool Trace::isReflection()
 {
     return reflection;
@@ -997,7 +1322,7 @@ unsigned int Trace::getFileParameter() const
 
 double Trace::getNoise(double frequency)
 {
-    if(!isLive() || !settings.valid || (_liveParam != LiveParameter::Port1 && _liveParam != LiveParameter::Port2) || lastMath->getDataType() != DataType::Frequency) {
+    if(source != Trace::Source::Live || !settings.valid || (_liveParam != LiveParameter::Port1 && _liveParam != LiveParameter::Port2) || lastMath->getDataType() != DataType::Frequency) {
         // data not suitable for noise calculation
         return std::numeric_limits<double>::quiet_NaN();
     }
diff --git a/Software/PC_Application/Traces/trace.h b/Software/PC_Application/Traces/trace.h
index 17802f1..d4cb415 100644
--- a/Software/PC_Application/Traces/trace.h
+++ b/Software/PC_Application/Traces/trace.h
@@ -6,7 +6,6 @@
 #include "Device/device.h"
 #include "Math/tracemath.h"
 #include "Tools/parameters.h"
-#include "tracemodel.h"
 #include "VNA/vnadata.h"
 
 #include <QObject>
@@ -14,8 +13,10 @@
 #include <map>
 #include <QColor>
 #include <set>
+#include <QTime>
 
 class Marker;
+class TraceModel;
 
 class Trace : public TraceMath
 {
@@ -24,6 +25,14 @@ public:
 
     using Data = TraceMath::Data;
 
+    enum class Source {
+        Live,
+        File,
+        Math,
+        Calibration,
+        Last,
+    };
+
     enum class LiveParameter {
         S11,
         S12,
@@ -44,7 +53,7 @@ public:
         Invalid,
     };
 
-    void clear();
+    void clear(bool force = false);
     void addData(const Data& d, DataType domain, double reference_impedance = 50.0, int index = -1);
     void addData(const Data& d, const Protocol::SpectrumAnalyzerSettings& s, int index = -1);
     void setName(QString name);
@@ -53,15 +62,14 @@ public:
     QString fillFromCSV(CSV &csv, unsigned int parameter); // returns the suggested trace name (not yet set in member data)
     static void fillFromDatapoints(Trace &S11, Trace &S12, Trace &S21, Trace &S22, const std::vector<VNAData> &data);
     void fromLivedata(LivedataType type, LiveParameter param);
+    void fromMath();
     QString name() { return _name; }
     QColor color() { return _color; }
     bool isVisible();
     void pause();
     void resume();
     bool isPaused();
-    bool isFromFile();
-    bool isCalibration();
-    bool isLive();
+    Source getSource() {return source;}
     bool isReflection();
     LiveParameter liveParameter() { return _liveParam; }
     LivedataType liveType() { return _liveType; }
@@ -92,7 +100,7 @@ public:
     double getNoise(double frequency);
     int index(double x);
     std::set<Marker *> getMarkers() const;
-    void setCalibration(bool value);
+    void setCalibration();
     void setReflection(bool value);
 
     DataType outputType(DataType inputType) override;
@@ -129,7 +137,7 @@ public:
     // When saving the current graph configuration, the pointer is not useful. Instead a trace
     // hash is saved to identify the correct trace. The hash should be influenced by every setting
     // the trace can have (and its math function). It should not depend on the acquired trace samples
-    unsigned int toHash();
+    unsigned int toHash(bool forceUpdate = false);
 
     static std::vector<Trace*> createFromTouchstone(Touchstone &t);
     static std::vector<Trace*> createFromCSV(CSV &csv);
@@ -148,12 +156,28 @@ public:
 
     double getReferenceImpedance() const;
 
+    void setModel(TraceModel *newModel);
+    TraceModel *getModel() const;
+
+    const QString &getMathFormula() const;
+    void setMathFormula(const QString &newMathFormula);
+    bool mathFormularValid() const;
+
+    bool resolveMathSourceHashes();
+
 public slots:
     void setVisible(bool visible);
     void setColor(QColor color);
     void addMarker(Marker *m);
     void removeMarker(Marker *m);
 
+    // functions for handling source == Source::Math
+    bool mathDependsOn(Trace *t, bool onlyDirectDependency = false);
+    bool canAddAsMathSource(Trace *t);
+    bool addMathSource(Trace *t, QString variableName);
+    void removeMathSource(Trace *t);
+    QString getSourceVariableName(Trace *t);
+
 signals:
     void cleared(Trace *t);
     void typeChanged(Trace *t);
@@ -170,21 +194,50 @@ signals:
 private slots:
     void markerVisibilityChanged(Marker *m);
 
+    // functions for handling source == Source::Math
+    bool updateMathTracePoints();
+    void mathSourceTraceDeleted(Trace *t);
+    void scheduleMathCalculation(unsigned int begin, unsigned int end);
+    void calculateMath();
+    void clearMathSources();
+
+    bool addMathSource(unsigned int hash, QString variableName);
+
 private:
+    TraceModel *model; // model which this trace will be part of
     QString _name;
     QColor _color;
+    Source source;
+
+    unsigned int hash;
+    bool hashSet;
+    bool JSONskipHash;
+
+    // Members for when source == Source::Live
     LivedataType _liveType;
     LiveParameter _liveParam;
+
+    // Members for when source == Source::File
+    QString filename;
+    unsigned int fileParameter;
+
+    // Members for when source == Source::Math
+    std::map<Trace*,QString> mathSourceTraces;
+    std::map<unsigned int,QString> mathSourceUnresolvedHashes;
+    QString mathFormula;
+    static constexpr int MinMathUpdateInterval = 100;
+    QTime lastMathUpdate;
+    QTimer mathCalcTimer;
+    unsigned int mathUpdateBegin;
+    unsigned int mathUpdateEnd;
+
     double vFactor;
     bool reflection;
     bool visible;
     bool paused;
-    bool createdFromFile;
-    bool calibration;
     double reference_impedance;
     DataType domain;
-    QString filename;
-    unsigned int fileParameter;
+
     std::set<Marker*> markers;
     struct {
         union {
diff --git a/Software/PC_Application/Traces/traceeditdialog.cpp b/Software/PC_Application/Traces/traceeditdialog.cpp
index c0e209f..853f8c7 100644
--- a/Software/PC_Application/Traces/traceeditdialog.cpp
+++ b/Software/PC_Application/Traces/traceeditdialog.cpp
@@ -26,6 +26,11 @@ TraceEditDialog::TraceEditDialog(Trace &t, QWidget *parent) :
     ui->impedance->setPrecision(3);
     ui->impedance->setValue(t.getReferenceImpedance());
 
+    if(!t.getModel()) {
+        // without information about the other traces in the model, math is not available as a source
+        ui->bMath->setEnabled(false);
+    }
+
     connect(ui->bLive, &QPushButton::clicked, [=](bool live) {
         if(live) {
             ui->stack->setCurrentIndex(0);
@@ -45,6 +50,12 @@ TraceEditDialog::TraceEditDialog(Trace &t, QWidget *parent) :
             }
         }
     });
+    connect(ui->bMath, &QPushButton::clicked, [&](bool math){
+       if(math) {
+           ui->stack->setCurrentIndex(3);
+           ui->buttonBox->button(QDialogButtonBox::Ok)->setEnabled(t.mathFormularValid());
+       }
+    });
 
     connect(ui->color, &ColorPickerButton::colorChanged, [=](const QColor& color){
        trace.setColor(color);
@@ -52,8 +63,9 @@ TraceEditDialog::TraceEditDialog(Trace &t, QWidget *parent) :
 
     ui->GSource->setId(ui->bLive, 0);
     ui->GSource->setId(ui->bFile, 1);
+    ui->GSource->setId(ui->bFile, 2);
 
-    if(t.isCalibration()) {
+    if(t.getSource() == Trace::Source::Calibration) {
         // prevent editing imported calibration traces (and csv files for now)
         ui->bLive->setEnabled(false);
         ui->bFile->setEnabled(false);
@@ -136,8 +148,83 @@ TraceEditDialog::TraceEditDialog(Trace &t, QWidget *parent) :
     connect(ui->touchstoneImport, &TouchstoneImport::filenameChanged, updateTouchstoneFileStatus);
     connect(ui->csvImport, &CSVImport::filenameChanged, updateCSVFileStatus);
 
-    if(t.isFromFile()) {
-        ui->bFile->click();
+    // Math source configuration
+    if(t.getModel()) {
+        ui->lMathFormula->setText(t.getMathFormula());
+        connect(ui->lMathFormula, &QLineEdit::editingFinished, [&](){
+            t.setMathFormula(ui->lMathFormula->text());
+            ui->buttonBox->button(QDialogButtonBox::Ok)->setEnabled(t.mathFormularValid());
+        });
+
+        ui->mathTraceTable->setColumnCount(2);
+        ui->mathTraceTable->setHorizontalHeaderItem(0, new QTableWidgetItem("Trace Name"));
+        ui->mathTraceTable->setHorizontalHeaderItem(1, new QTableWidgetItem("Variable Name"));
+        auto traces = t.getModel()->getTraces();
+        ui->mathTraceTable->setRowCount(traces.size());
+        for(unsigned int i=0;i<traces.size();i++) {
+            auto ts = traces[i];
+            auto traceItem = new QTableWidgetItem(ts->name());
+            auto flags = traceItem->flags() | Qt::ItemIsUserCheckable;
+            flags &= ~(Qt::ItemIsEditable | Qt::ItemIsEnabled);
+            if(t.canAddAsMathSource(ts)) {
+                flags |= Qt::ItemIsEnabled;
+            }
+            traceItem->setFlags(flags);
+            auto variableItem = new QTableWidgetItem(t.getSourceVariableName(ts));
+            variableItem->setFlags(variableItem->flags() & ~Qt::ItemIsEditable);
+            if(t.mathDependsOn(ts, true)) {
+                traceItem->setCheckState(Qt::Checked);
+                variableItem->setFlags(variableItem->flags() | Qt::ItemIsEnabled | Qt::ItemIsEditable);
+            } else {
+                traceItem->setCheckState(Qt::Unchecked);
+            }
+            ui->mathTraceTable->setItem(i, 0, traceItem);
+            ui->mathTraceTable->setItem(i, 1, variableItem);
+        }
+        connect(ui->mathTraceTable, &QTableWidget::itemChanged, [&](QTableWidgetItem *item){
+            auto row = ui->mathTraceTable->row(item);
+            auto column = ui->mathTraceTable->column(item);
+            qDebug() << "Item changed at row"<<row<<"column"<<column;
+            ui->mathTraceTable->blockSignals(true);
+            auto trace = t.getModel()->trace(row);
+            if(column == 0) {
+                auto variableItem = ui->mathTraceTable->item(row, 1);
+                // checked state changed
+                if(item->checkState() == Qt::Checked) {
+                    // add this trace to the math sources, enable editing of variable name
+                    t.addMathSource(trace, trace->name());
+                    variableItem->setText(trace->name());
+                    variableItem->setFlags(variableItem->flags() | Qt::ItemIsEnabled | Qt::ItemIsEditable);
+                } else {
+                    // trace disabled, remove from math sources
+                    t.removeMathSource(trace);
+                    variableItem->setText("");
+                    variableItem->setFlags(variableItem->flags() & ~(Qt::ItemIsEnabled | Qt::ItemIsEditable));
+                }
+                // available trace selections may have changed, disable/enable other rows
+                for(unsigned int i=0;i<t.getModel()->getTraces().size();i++) {
+                    auto traceItem = ui->mathTraceTable->item(i, 0);
+                    auto flags = traceItem->flags();
+                    if(t.canAddAsMathSource(t.getModel()->trace(i))) {
+                        traceItem->setFlags(flags | Qt::ItemIsEnabled);
+                    } else {
+                        traceItem->setFlags(flags & ~Qt::ItemIsEnabled);
+                    }
+                }
+            } else {
+                // changed the variable name text
+                t.addMathSource(trace, item->text());
+            }
+            ui->mathTraceTable->blockSignals(false);
+            ui->buttonBox->button(QDialogButtonBox::Ok)->setEnabled(t.mathFormularValid());
+        });
+    }
+
+    switch(t.getSource()) {
+    case Trace::Source::Live: ui->bLive->click(); break;
+    case Trace::Source::File: ui->bFile->click(); break;
+    case Trace::Source::Math: ui->bMath->click(); break;
+    default: break;
     }
 
     // setup math part of the GUI
@@ -254,7 +341,7 @@ void TraceEditDialog::on_buttonBox_accepted()
 {
     trace.setName(ui->name->text());
     trace.setVelocityFactor(ui->vFactor->value());
-    if(!trace.isCalibration()) {
+    if(trace.getSource() != Trace::Source::Calibration) {
         // only apply changes if it is not a calibration trace
         if (ui->bFile->isChecked()) {
             if(ui->stack->currentIndex() == 1) {
@@ -265,7 +352,7 @@ void TraceEditDialog::on_buttonBox_accepted()
                 // CSV page active
                 ui->csvImport->fillTrace(trace);
             }
-        } else {
+        } else if(ui->bLive->isChecked()) {
             Trace::LivedataType type = Trace::LivedataType::Overwrite;
             Trace::LiveParameter param = Trace::LiveParameter::S11;
             switch(ui->CLiveType->currentIndex()) {
@@ -287,6 +374,9 @@ void TraceEditDialog::on_buttonBox_accepted()
                 }
             }
             trace.fromLivedata(type, param);
+        } else {
+            // math operation trace
+            trace.fromMath();
         }
     }
     delete this;
diff --git a/Software/PC_Application/Traces/traceeditdialog.ui b/Software/PC_Application/Traces/traceeditdialog.ui
index 35e283c..24bae6c 100644
--- a/Software/PC_Application/Traces/traceeditdialog.ui
+++ b/Software/PC_Application/Traces/traceeditdialog.ui
@@ -9,8 +9,8 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>931</width>
-    <height>392</height>
+    <width>979</width>
+    <height>487</height>
    </rect>
   </property>
   <property name="windowTitle">
@@ -110,6 +110,16 @@
            </attribute>
           </widget>
          </item>
+         <item>
+          <widget class="QRadioButton" name="bMath">
+           <property name="text">
+            <string>From Math</string>
+           </property>
+           <attribute name="buttonGroup">
+            <string notr="true">GSource</string>
+           </attribute>
+          </widget>
+         </item>
         </layout>
        </item>
        <item>
@@ -133,7 +143,7 @@
        <item>
         <widget class="QStackedWidget" name="stack">
          <property name="currentIndex">
-          <number>0</number>
+          <number>3</number>
          </property>
          <widget class="QWidget" name="LivePage">
           <layout class="QFormLayout" name="formLayout_2">
@@ -203,6 +213,34 @@
            </item>
           </layout>
          </widget>
+         <widget class="QWidget" name="MathPage">
+          <layout class="QVBoxLayout" name="verticalLayout_7">
+           <item>
+            <widget class="QTableWidget" name="mathTraceTable">
+             <attribute name="horizontalHeaderStretchLastSection">
+              <bool>true</bool>
+             </attribute>
+             <attribute name="verticalHeaderVisible">
+              <bool>false</bool>
+             </attribute>
+            </widget>
+           </item>
+           <item>
+            <layout class="QHBoxLayout" name="horizontalLayout_7">
+             <item>
+              <widget class="QLabel" name="label_8">
+               <property name="text">
+                <string>Formula:</string>
+               </property>
+              </widget>
+             </item>
+             <item>
+              <widget class="QLineEdit" name="lMathFormula"/>
+             </item>
+            </layout>
+           </item>
+          </layout>
+         </widget>
         </widget>
        </item>
       </layout>
diff --git a/Software/PC_Application/Traces/tracemodel.cpp b/Software/PC_Application/Traces/tracemodel.cpp
index d3915a7..e28a243 100644
--- a/Software/PC_Application/Traces/tracemodel.cpp
+++ b/Software/PC_Application/Traces/tracemodel.cpp
@@ -32,6 +32,7 @@ void TraceModel::addTrace(Trace *t)
     });
     traces.push_back(t);
     endInsertRows();
+    t->setModel(this);
     emit traceAdded(t);
 }
 
@@ -117,7 +118,7 @@ QVariant TraceModel::data(const QModelIndex &index, int role) const
         }
         break;
     case ColIndexPlayPause:
-        if (role == Qt::DecorationRole && trace->isLive()) {
+        if (role == Qt::DecorationRole && trace->getSource() == Trace::Source::Live) { // TODO trace needs function to check if it may change due to live data
             if (trace->isPaused()) {
                 return QIcon(":/icons/pause.svg");
             } else {
@@ -157,7 +158,7 @@ std::vector<Trace *> TraceModel::getTraces() const
 bool TraceModel::PortExcitationRequired(int port)
 {
     for(auto t : traces) {
-        if(t->isLive() && !t->isPaused()) {
+        if(t->getSource() == Trace::Source::Live && !t->isPaused()) {
             // this trace needs measurements from VNA, check if port has to be excited for its measurement
             auto param = t->liveParameter();
             if(port == 1 && (param == Trace::LiveParameter::S11 || param == Trace::LiveParameter::S21)) {
@@ -188,6 +189,7 @@ void TraceModel::fromJSON(nlohmann::json j)
     }
     for(auto jt : j) {
         auto trace = new Trace();
+        trace->setModel(this);
         try {
             trace->fromJSON(jt);
             addTrace(trace);
@@ -195,12 +197,17 @@ void TraceModel::fromJSON(nlohmann::json j)
             qWarning() << "Failed to create trace:" << e.what();
         }
     }
+    for(auto t : traces) {
+        if(!t->resolveMathSourceHashes()) {
+            qWarning() << "Failed to resolve all math source hashes for"<<t;
+        }
+    }
 }
 
 void TraceModel::clearLiveData()
 {
     for(auto t : traces) {
-        if (t->isLive()) {
+        if (t->getSource() == Trace::Source::Live) {
             // this trace is fed from live data
             t->clear();
         }
@@ -211,7 +218,7 @@ void TraceModel::addVNAData(const VNAData& d, TraceMath::DataType datatype)
 {
     source = DataSource::VNA;
     for(auto t : traces) {
-        if (t->isLive() && !t->isPaused()) {
+        if (t->getSource() == Trace::Source::Live && !t->isPaused()) {
             int index = -1;
             Trace::Data td;
             switch(datatype) {
@@ -247,7 +254,7 @@ void TraceModel::addSAData(const Protocol::SpectrumAnalyzerResult& d, const Prot
 {
     source = DataSource::SA;
     for(auto t : traces) {
-        if (t->isLive() && !t->isPaused()) {
+        if (t->getSource() == Trace::Source::Live && !t->isPaused()) {
             int index = -1;
             Trace::Data td;
             if(settings.f_start == settings.f_stop) {
diff --git a/Software/PC_Application/Traces/tracewidget.cpp b/Software/PC_Application/Traces/tracewidget.cpp
index a7504c4..082944b 100644
--- a/Software/PC_Application/Traces/tracewidget.cpp
+++ b/Software/PC_Application/Traces/tracewidget.cpp
@@ -426,6 +426,8 @@ void TraceWidget::contextMenuEvent(QContextMenuEvent *event)
         auto duplicate = new Trace();
         duplicate->fromJSON(json);
         duplicate->setName(duplicate->name() + " - Duplicate");
+        // force update of hash
+        duplicate->toHash(true);
         model.addTrace(duplicate);
     });
     ctxmenu->addAction(action_duplicate);