JKQtPlotter/examples/filledgraphs_errors

Example (JKQTPlotter): Filled Graphs with Error Indicators

This project (see filledgraphs_errors shows how to draw filled graphs with different styles of error indicators.

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

    // 1. create a plotter window and get a pointer to the internal datastore (for convenience)
    JKQTPlotter plot;
    JKQTPDatastore* ds=plot.getDatastore();

    // 2. now we create two columns for key and value
    size_t columnK=ds->addLinearColumn(10, 0, 2.0*JKQTPSTATISTICS_PI,"k");
    size_t columnV=ds->addColumnCalculatedFromColumn(columnK, &cos, "v");

    // 3. create graph in the plot, which plots the dataset:
    JKQTPBarGraphBase* graph=new JKQTPBarVerticalGraph(&plot);
    graph->setKeyColumn(columnK);
    graph->setValueColumn(columnV);
    // set TwoColor fill Mode
    graph->setFillMode(JKQTPBarGraphBase::FillMode::TwoColorFilling);
    graph->setFillColor(QColor("green"));
    graph->fillStyleBelow().setFillColor(QColor("red"));
    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: