Example (JKQTPlotter): Barchart With Functor Fill-Mode

This project (see barchart_functorfill shows how to draw barcharts, where the bars are filled differently, as defined by a custom functor.

The source code of the main application is (see barchart_functorfill.cpp:

    // 1. create a plotter window and get a pointer to the internal datastore (for convenience)
JKQTPDatastore* ds=plot.getDatastore();
 
// 2. now we create two columns for key and value
size_t columnK=ds->addLinearColumn(11, 0, 10, "k");
size_t columnV=ds->addColumnCalculatedFromColumn(columnK, [](double x) { return 5.0+x; }, "v");
 
// 3. create graph in the plot, which plots the dataset:
JKQTPBarVerticalGraph* graph=new JKQTPBarVerticalGraph(&plot);
graph->setKeyColumn(columnK);
graph->setValueColumn(columnV);
// set FunctorFilling fill Mode
graph->setFillMode(JKQTPBarGraphBase::FillMode::FunctorFilling);
// define filling functor
graph->setFillBrushFunctor(
  [](double key, double value) {
    return QBrush(QColor::fromHsvF(key/12.0, 1.0, 1.0)); 
  }
);
plot.addGraph(graph);
 
// 4 autoscale the plot so the graph is contained
plot.zoomToFit();
 
// 5. show plotter and make it a decent size
plot.setWindowTitle(title);
plot.show();
plot.resize(400,400);

The result looks like this:

In order to draw horizontal error bars, you have to use JKQTPBarHorizontalGraph instead of JKQTPBarVerticalGraph: