JKQtPlotter/examples/simpletest_stackedbars/README.md

# Example (JKQTPlotter): Simple stacked barchart {#JKQTPlotterStackedBarChart}
This project (see `./examples/simpletest_stackedbars/`) simply creates a JKQTPlotter widget (as a new window) and adds several stacked barcharts.

The source code of the main application is (see [`jkqtplotter_simpletest_stackedbars.cpp`](https://github.com/jkriege2/JKQtPlotter/tree/master/examples/simpletest_stackedbars/jkqtplotter_simpletest_stackedbars.cpp):
```.cpp
#include <QApplication>
#include "jkqtplotter/jkqtplotter.h"
#include "jkqtplotter/graphs/jkqtpbarchart.h"

#define Ndata 5
int main(int argc, char* argv[])
{
    QApplication app(argc, argv);

    // 1. create a plotter window and get a pointer to the internal datastore (for convenience)
	JKQTPlotter plot;
    plot.getPlotter()->setUseAntiAliasingForGraphs(true); // nicer (but slower) plotting
    plot.getPlotter()->setUseAntiAliasingForSystem(true); // nicer (but slower) plotting
    plot.getPlotter()->setUseAntiAliasingForText(true); // nicer (but slower) text rendering
    JKQTPDatastore* ds=plot.getDatastore();

    // 2. now we create data for the charts (taken from https://commons.wikimedia.org/wiki/File:Energiemix_Deutschland.svg)
    QVector<double> year, percentage_other, percentage_coaloil, percentage_gas, percentage_nuclear, percentage_green;
    year                << 1990     << 1995     << 2000     << 2005     << 2010     << 2015;
    percentage_other    << 3.5      << 3.5      << 4.4      << 4.4      << 5        << 5   ;
    percentage_coaloil  << 58.7     << 55.7     << 51.5     << 48.2     << 42.9     << 43.1;
    percentage_gas      << 6.5      << 7.7      << 8.5      << 11.7     << 14.1     << 9.6 ;
    percentage_nuclear  << 27.7     << 28.7     << 29.4     << 26.2     << 22.2     << 14.2;
    percentage_green    << 3.6      << 4.4      << 6.2      << 9.5      << 15.8     << 28.1;


    // 3. make data available to JKQTPlotter by adding it to the internal datastore.
    //    Note: In this step the data is copied (of not specified otherwise)
    //    the variables cYear, cOther ... will contain the internal column ID of the
    //    newly created columns with names "year" and "other" ... and the (copied) data
    size_t cYear=ds->addCopiedColumn(year, "year");
    size_t cOther=ds->addCopiedColumn(percentage_other, "other");
    size_t cCoalOil=ds->addCopiedColumn(percentage_coaloil, "coal & oil");
    size_t cGas=ds->addCopiedColumn(percentage_gas, "natural gas");
    size_t cNuclear=ds->addCopiedColumn(percentage_nuclear, "nuclear energy");
    size_t cGreen=ds->addCopiedColumn(percentage_green, "green energy");

    // 4. create graphs in the plot, which plots the dataset year/other, year/coal, ...
    //    The color of the graphs is set by calling setFillColor_and_darkenedColor(), which sets the
    //    fillColor to the given color and makes the outline of the bars (i.e. their "color") a darker
    //    shade of the given color.
    QVector<JKQTPBarVerticalStackableGraph*> graphs;
    graphs.push_back(new JKQTPBarVerticalStackableGraph(&plot));
    graphs.back()->setXColumn(cYear);
    graphs.back()->setYColumn(cOther);
    graphs.back()->setTitle(QObject::tr("other sources"));
    graphs.back()->setFillColor_and_darkenedColor(QColor("red"));
    graphs.push_back(new JKQTPBarVerticalStackableGraph(&plot));
    graphs.back()->setXColumn(cYear);
    graphs.back()->setYColumn(cCoalOil);
    graphs.back()->setTitle(QObject::tr("coal & oil"));
    graphs.back()->setFillColor_and_darkenedColor(QColor("darkgrey"));
    graphs.back()->stackUpon(graphs[graphs.size()-2]);
    graphs.push_back(new JKQTPBarVerticalStackableGraph(&plot));
    graphs.back()->setXColumn(cYear);
    graphs.back()->setYColumn(cGas);
    graphs.back()->setTitle(QObject::tr("natural gas"));
    graphs.back()->setFillColor_and_darkenedColor(QColor("blue"));
    graphs.back()->stackUpon(graphs[graphs.size()-2]);
    graphs.push_back(new JKQTPBarVerticalStackableGraph(&plot));
    graphs.back()->setXColumn(cYear);
    graphs.back()->setYColumn(cNuclear);
    graphs.back()->setTitle(QObject::tr("nuclear energy"));
    graphs.back()->setFillColor_and_darkenedColor(QColor("gold"));
    graphs.back()->stackUpon(graphs[graphs.size()-2]);
    graphs.push_back(new JKQTPBarVerticalStackableGraph(&plot));
    graphs.back()->setXColumn(cYear);
    graphs.back()->setYColumn(cGreen);
    graphs.back()->setTitle(QObject::tr("green energy"));
    graphs.back()->setFillColor_and_darkenedColor(QColor("darkgreen"));
    graphs.back()->stackUpon(graphs[graphs.size()-2]);


    // 5. add the graphs to the plot, so it is actually displayed
    plot.addGraphs(graphs);

    // 6. set axis labels
    plot.getXAxis()->setAxisLabel("year");
    plot.getYAxis()->setAxisLabel("fraction of energy production in Germany [%]");

    // 7. finally we move the plot key/legend to the outside, top-right
    //    and lay it out as a single row
    //    NOTE: plot is a descendent of QWidget, which uses an internal object of
    //          type JKQTBasePlotter, which does the actual plotting.
    //          So many properties of the plot are only available in this internal
    //          object, which you can access by plot.getPlotter().
    plot.getPlotter()->setKeyPosition(JKQTPKeyOutsideTopRight);
    plot.getPlotter()->setKeyLayout(JKQTPKeyLayoutOneRow);

    // 8 autoscale the plot so the graph is contained
    plot.zoomToFit();

    // show plotter and make it a decent size
    plot.show();
    plot.resize(600,400);
	
	return app.exec();
}
```
The result looks like this:

![JKQTPBarVerticalGraphStacked](https://raw.githubusercontent.com/jkriege2/JKQTPlotter/master/doc/images/JKQTPbarVerticalGraphStacked.png)

If you use `JKQTPBarHorizontalGraphStacked` instead of `JKQTPBarVerticalStackableGraph`, you'll get a result like this: 
![JKQTPBarHorizontalGraphStacked](https://raw.githubusercontent.com/jkriege2/JKQTPlotter/master/doc/images/JKQTPbarHorizontalGraphStacked.png)