ChartDirector 6.0 (C++ Edition)

Waterfall Chart




This example demonstrates creating a multi-color waterfall chart.

This chart is created as a multi-color box-whisker layer using XYChart.addBoxWhiskerLayer2. Only the "box" part of the box-whisker layer is used.

The top-edges of the boxes are obtained by accumulating the raw data using the ArrayMath utility. The bottom-edges of the boxes are simply the top-edges of previous boxes, with the exception of the last "total" box which always starts at 0.

Source Code Listing

[The following code is available in "cppdemo/waterfall". 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[])
{
    // 4 data points to represent the cash flow for the Q1 - Q4
    double data[] = {230, 140, 220, 330, 150};

    // We want to plot a waterfall chart showing the 4 quarters as well as the total
    const char *labels[] = {"Product 1", "Product 2", "Product 3", "Product 4", "Product 5", "Total"
        };

    // The top side of the bars in a waterfall chart is the accumulated data. We use the
    // ChartDirector ArrayMath utility to accumulate the data. The "total" is handled by inserting a
    // zero point at the end before accumulation (after accumulation it will become the total).
    ArrayMath boxTop = ArrayMath(DoubleArray(data, (int)(sizeof(data) / sizeof(data[0])))).insert(0,
        1).acc();

    // The botom side of the bars is just the top side of the previous bar. So we shifted the top
    // side data to obtain the bottom side data.
    ArrayMath boxBottom = ArrayMath(boxTop).shift(1, 0);

    // The last point (total) is different. Its bottom side is always 0.
    boxBottom.trim(0, (int)(sizeof(data) / sizeof(data[0]))).insert(0, 1);

    // Create a XYChart object of size 500 x 280 pixels. Set background color to light blue
    // (ccccff), with 1 pixel 3D border effect.
    XYChart *c = new XYChart(500, 290, 0xccccff, 0x000000, 1);

    // Add a title to the chart using 13 points Arial Bold Itatic font, with white (ffffff) text on
    // a deep blue (0x80) background
    c->addTitle("Product Revenue - Year 2004", "arialbi.ttf", 13, 0xffffff)->setBackground(0x000080)
        ;

    // Set the plotarea at (55, 50) and of size 430 x 215 pixels. Use alternative white/grey
    // background.
    c->setPlotArea(55, 45, 430, 215, 0xffffff, 0xeeeeee);

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

    // Set the x-axis ticks and grid lines to be between the bars
    c->xAxis()->setTickOffset(0.5);

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

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

    // Add a multi-color box-whisker layer to represent the waterfall bars
    BoxWhiskerLayer *layer = c->addBoxWhiskerLayer2(boxTop, boxBottom);

    // Put data labels on the bars to show the cash flow using Arial Bold font
    layer->setDataLabelFormat("{={top}-{bottom}}M");
    layer->setDataLabelStyle("arialbd.ttf")->setAlignment(Chart::Center);

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

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