Added variance calculation to plot window

src/ui/linechart/LinechartPlot.cc

@@ -198,6 +198,14 @@ double LinechartPlot::getMedian(QString id)
     return data.value(id)->getMedian();
 }
 
+/**
+ * @param id curve identifier
+ */
+double LinechartPlot::getVariance(QString id)
+{
+    return data.value(id)->getVariance();
+}
+
 int LinechartPlot::getAverageWindow()
 {
     return averageWindowSize;
@@ -743,8 +751,9 @@ TimeSeriesData::TimeSeriesData(QwtPlot* plot, QString friendlyName, quint64 plot
         maxValue(DBL_MIN),
         zeroValue(0),
         count(0),
-        mean(0.00),
-        median(0.00),
+        mean(0.0),
+        median(0.0),
+        variance(0.0),
         averageWindow(50)
 {
     this->plot = plot;
@@ -802,6 +811,14 @@ void TimeSeriesData::append(quint64 ms, double value)
         medianList.append(this->value[count-i]);
     }
     mean = mean / static_cast<double>(qMin(averageWindow,static_cast<unsigned int>(count)));
+
+    this->variance = 0;
+    for (unsigned int i = 0; (i < averageWindow) && (((int)count - (int)i) >= 0); ++i)
+    {
+       this->variance += (this->value[count-i] - mean) * (this->value[count-i] - mean);
+    }
+    this->variance = this->variance / static_cast<double>(qMin(averageWindow,static_cast<unsigned int>(count)));
+
     qSort(medianList);
 
     if (medianList.count() > 2)
@@ -901,6 +918,14 @@ double TimeSeriesData::getMedian()
     return median;
 }
 
+/**
+ * @return the variance
+ */
+double TimeSeriesData::getVariance()
+{
+    return variance;
+}
+
 double TimeSeriesData::getCurrentValue()
 {
     return lastValue;

src/ui/linechart/LinechartPlot.h

@@ -132,6 +132,8 @@ public:
     double getMean();
     /** @brief Get the short-term median */
     double getMedian();
+    /** @brief Get the short-term variance */
+    double getVariance();
     /** @brief Get the current value */
     double getCurrentValue();
     void setZeroValue(double zeroValue);
@@ -166,6 +168,7 @@ private:
     QwtArray<double> value;
     double mean;
     double median;
+    double variance;
     unsigned int averageWindow;
     QwtArray<double> outputMs;
     QwtArray<double> outputValue;
@@ -208,6 +211,8 @@ public:
     double getMean(QString id);
     /** @brief Get the short-term median of a curve */
     double getMedian(QString id);
+    /** @brief Get the short-term variance of a curve */
+    double getVariance(QString id);
     /** @brief Get the last inserted value */
     double getCurrentValue(QString id);
 

src/ui/linechart/LinechartWidget.cc

@@ -63,6 +63,7 @@ listedCurves(new QList<QString>()),
 curveLabels(new QMap<QString, QLabel*>()),
 curveMeans(new QMap<QString, QLabel*>()),
 curveMedians(new QMap<QString, QLabel*>()),
+curveVariances(new QMap<QString, QLabel*>()),
 curveMenu(new QMenu(this)),
 logFile(new QFile()),
 logindex(1),
@@ -268,6 +269,13 @@ void LinechartWidget::refresh()
 //        str.sprintf("%+.2f", activePlot->getMedian(k.key()));
 //        k.value()->setText(str);
 //    }
+    QMap<QString, QLabel*>::iterator l;
+    for (l = curveVariances->begin(); l != curveVariances->end(); ++l)
+    {
+      // Variance
+       str.sprintf("%+.5f", activePlot->getVariance(l.key()));
+      l.value()->setText(str);
+   }
 }
 
 
@@ -388,6 +396,7 @@ QWidget* LinechartWidget::createCurveItem(QString curve)
     QLabel* label;
     QLabel* value;
     QLabel* mean;
+    QLabel* variance;
     form->setAutoFillBackground(false);
     horizontalLayout = new QHBoxLayout(form);
     horizontalLayout->setSpacing(5);
@@ -437,6 +446,12 @@ QWidget* LinechartWidget::createCurveItem(QString curve)
 //    curveMedians->insert(curve, median);
 //    horizontalLayout->addWidget(median);
 
+    // Variance
+    variance = new QLabel(form);
+    variance->setNum(0.00);
+    curveVariances->insert(curve, variance);
+    horizontalLayout->addWidget(variance);
+
     /* Color picker
     QColor color = QColorDialog::getColor(Qt::green, this);
          if (color.isValid()) {
@@ -453,6 +468,7 @@ QWidget* LinechartWidget::createCurveItem(QString curve)
     horizontalLayout->setStretchFactor(value, 50);
     horizontalLayout->setStretchFactor(mean, 50);
 //    horizontalLayout->setStretchFactor(median, 50);
+    horizontalLayout->setStretchFactor(variance, 50);
 
     // Connect actions
     QObject::connect(checkBox, SIGNAL(clicked(bool)), this, SLOT(takeButtonClick(bool)));

src/ui/linechart/LinechartWidget.h

@@ -109,6 +109,7 @@ protected:
     QMap<QString, QLabel*>* curveLabels;  ///< References to the curve labels
     QMap<QString, QLabel*>* curveMeans;   ///< References to the curve means
     QMap<QString, QLabel*>* curveMedians; ///< References to the curve medians
+    QMap<QString, QLabel*>* curveVariances; ///< References to the curve variances
 
     QWidget* curvesWidget;                ///< The QWidget containing the curve selection button
     QVBoxLayout* curvesWidgetLayout;      ///< The layout for the curvesWidget QWidget