ChartDirector 6.0 (C++ Edition)

Positive Negative Bars




This example demonstrates a bar chart containing positive and negative data, represented by different colors.

In this example, the two colors of the plot area background are configured using background zones, while the bar colors are configured by splitting the bars into two layers.

Source Code Listing

[The following code is available in "cppdemo/posnegbar". A MFC version of the code is available in "mfcdemo/mfcdemo" (Windows edition only). A QT version of the code is available in "qtdemo/qtdemo".]
#include "chartdir.h"

int main(int argc, char *argv[])
{
    // The data for the bar chart
    double data[] = {-6.3, 2.3, 0.7, -3.4, 2.2, -2.9, -0.1, -0.1, 3.3, 6.2, 4.3, 1.6};

    // The labels for the bar chart
    const char *labels[] = {"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct",
        "Nov", "Dec"};

    // Create a XYChart object of size 500 x 320 pixels
    XYChart *c = new XYChart(500, 320);

    // Add a title to the chart using Arial Bold Italic font
    c->addTitle("Productivity Change - Year 2005", "arialbi.ttf");

    // Set the plotarea at (50, 30) and of size 400 x 250 pixels
    c->setPlotArea(50, 30, 400, 250);

    // Add a bar layer to the chart using the Overlay data combine method
    BarLayer *layer = c->addBarLayer(Chart::Overlay);

    // Select positive data and add it as data set with blue (6666ff) color
    layer->addDataSet(ArrayMath(DoubleArray(data, (int)(sizeof(data) / sizeof(data[0])))).selectGEZ(
        DoubleArray(), Chart::NoValue), 0x6666ff);

    // Select negative data and add it as data set with orange (ff6600) color
    layer->addDataSet(ArrayMath(DoubleArray(data, (int)(sizeof(data) / sizeof(data[0])))).selectLTZ(
        DoubleArray(), Chart::NoValue), 0xff6600);

    // Add labels to the top of the bar using 8 pt Arial Bold font. The font color is configured to
    // be red (0xcc3300) below zero, and blue (0x3333ff) above zero.
    layer->setAggregateLabelStyle("arialbd.ttf", 8, layer->yZoneColor(0, 0xcc3300, 0x3333ff));

    // Set the labels on the x axis and use Arial Bold as the label font
    c->xAxis()->setLabels(StringArray(labels, (int)(sizeof(labels) / sizeof(labels[0])))
        )->setFontStyle("arialbd.ttf");

    // Draw the y axis on the right of the plot area
    c->setYAxisOnRight(true);

    // Use Arial Bold as the y axis label font
    c->yAxis()->setLabelStyle("arialbd.ttf");

    // Add a title to the y axis
    c->yAxis()->setTitle("Percentage");

    // Add a light blue (0xccccff) zone for positive part of the plot area
    c->yAxis()->addZone(0, 9999, 0xccccff);

    // Add a pink (0xffffcc) zone for negative part of the plot area
    c->yAxis()->addZone(-9999, 0, 0xffcccc);

    // Output the chart
    c->makeChart("posnegbar.png");

    //free up resources
    delete c;
    return 0;
}