JKQtPlotter/examples/test_styledboxplot/README.md

Example (JKQTPlotter): Styling different aspects of boxplots

This project (see test_styledboxplot demonstrates how to style different aspects of boxplots and how to draw different types and styles of boxplots. For a simple introduction into how to use boxplots, see Plotting Box Plots and Plotting a Statistical Distribution of Data.

[JKQTPlotterBasicJKQTPDatastore]: @ref JKQTPlotterBasicJKQTPDatastore "Basic Usage of JKQTPDatastore" [JKQTPlotterBasicJKQTPDatastoreIterators]: @ref JKQTPlotterBasicJKQTPDatastoreIterators "Iterator-Based usage of JKQTPDatastore" [JKQTPlotterBasicJKQTPDatastoreStatistics]: @ref JKQTPlotterBasicJKQTPDatastoreStatistics "Advanced 1-Dimensional Statistics with JKQTPDatastore" [JKQTPlotterBasicJKQTPDatastoreRegression]: @ref JKQTPlotterBasicJKQTPDatastoreRegression "Regression Analysis (with the Statistics Library)" [JKQTPlotterBasicJKQTPDatastoreStatistics2D]: @ref JKQTPlotterBasicJKQTPDatastoreStatistics2D "Advanced 2-Dimensional Statistics with JKQTPDatastore" [statisticslibrary]: @ref jkqtptools_math_statistics "JKQTPlotter Statistics Library" [JKQTPlotterBoxplotStyling]: @ref JKQTPlotterBoxplotStyling "Styling different aspects of boxplots" [JKQTPlotterBoxplotsGraphs]: @ref JKQTPlotterBoxplotsGraphs "Boxplots"

Note that this example explains how to style boxplots. The example [JKQTPlotterBoxplotsGraphs] explains basics of how to create boxplots. The internal [statisticslibrary] offers methods to calculate the statistical properties necessary for boxplots, which is explained in the tutorial [JKQTPlotterBasicJKQTPDatastoreStatistics] in detail.

The link http://vita.had.co.nz/papers/boxplots.pdf leads to a paper that described the history and different types of boxplots.

The source code of the main application can be found in test_styledboxplot.cpp. The major parts that are concerned with the styling are:

    // 2. create a basic boxplot
    plot.addGraph(graphBoxPlot=new JKQTPBoxplotVerticalElement(&plot));
    plot.addGraph(new JKQTPGeoText(&plot, x-dx/2.0, y0+9, "\\textbf{\\begin{matrix}basic boxplot\\\\\"Turkey's style\"\\end{matrix}}", 8, QColor("black")));
    graphBoxPlot->setPos(x);
    graphBoxPlot->setMin(y0+1);
    graphBoxPlot->setPercentile25(y0+2.5);
    graphBoxPlot->setMedian(y0+4);
    graphBoxPlot->setPercentile75(y0+5.5);
    graphBoxPlot->setMax(y0+8);
    // set color of all elements
    graphBoxPlot->setBoxplotColor(QColor("black"),QColor("white"), plot.getPlotter());

    // ...
    // ...

    // 3. create a basic boxplot with mean as symbol
    // ...
    // set mean value to show mean symbol
    graphBoxPlot->setMean(y0+3.5);
    graphBoxPlot->setDrawMean(true);
    graphBoxPlot->setMeanMode(JKQTPGraphBoxplotStyleMixin::MeanAsSymbol);
    graphBoxPlot->setMeanColor(QColor("darkgreen"));
    graphBoxPlot->setMeanSymbolType(JKQTPFilledTriangle);

    // ...
    // ...

    // 4. create a basic boxplot with mean as line
    // ...
    // set mean value to show mean symbol
    graphBoxPlot->setMean(y0+3.5);
    graphBoxPlot->setDrawMean(true);
    graphBoxPlot->setMeanMode(JKQTPGraphBoxplotStyleMixin::MeanAsLine);
    graphBoxPlot->setMeanColor(QColor("darkgreen"));
    graphBoxPlot->setMeanLineStyle(Qt::DashLine);
    graphBoxPlot->setMeanLineWidth(2);

    // ...
    // ...

    // 5. create a notched boxplot
    // ...
    // for a notched plot, you need to set the confidence interval
    graphBoxPlot->setMedianConfidenceIntervalWidth(1);
    graphBoxPlot->setDrawNotch(true);
    graphBoxPlot->setRelativeNotchIndent(y0+0.5);

    // ...
    // ...

    // 6. create a notched boxplot
    // ...
    // restyle as Tufte's box-less
    graphBoxPlot->setDrawBox(false);

    // ...
    // ...

    // 7. style box
    // ...
    // style box line&fill
    graphBoxPlot->setLineColor(QColor("red"));
    graphBoxPlot->setLineStyle(Qt::DotLine);
    graphBoxPlot->setLineWidth(1);
    graphBoxPlot->setFillColor(QColor("yellow"));

    // ...
    // ...

    // 8. fancy style box
    // ...
    // style box fill
    QLinearGradient linearGrad(QPointF(0, 0), QPointF(1, 1));
    QColor c1(Qt::red);
    QColor c2(Qt::yellow);
    QColor c3(Qt::blue);
    linearGrad.setColorAt(0, c1);
    linearGrad.setColorAt(0.3, c2);
    linearGrad.setColorAt(1, c3);
    // use this CoordinateMode, so the gradient fills the whole graph area
    linearGrad.setCoordinateMode(QGradient::ObjectBoundingMode);
    graphBoxPlot->setFillGradient(linearGrad);

    // ...
    // ...

    // 9. style median
    // ...
    // style box line
    graphBoxPlot->setMedianLineColor(QColor("red"));
    graphBoxPlot->setMedianLineWidth(3);

    // ...
    // ...

    // 10. style whiskers&caps
    // ...
    // style box line
    graphBoxPlot->setWhiskerLineColor(QColor("red"));
    graphBoxPlot->setWhiskerLineStyle(Qt::DotLine);
    graphBoxPlot->setWhiskerLineWidth(1);
    graphBoxPlot->setWhiskerCapLineColor(QColor("blue"));
    graphBoxPlot->setWhiskerCapLineStyle(Qt::SolidLine);
    graphBoxPlot->setWhiskerCapLineWidth(4);
    graphBoxPlot->setRelativeWhiskerWidth(0.9);

The result looks like this: