ChartDirector 6.0 (C++ Edition)

Spline Line Chart




This example demonstrates using spline curves to join data points, title with soft lighting effect, as well as a number of chart formatting techniques.

Source Code Listing

[The following code is available in "cppdemo/splineline". 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 chart
    double data0[] = {32, 39, 23, 28, 41, 38, 26, 35, 29};
    double data1[] = {50, 55, 47, 34, 47, 53, 38, 40, 51};

    // The labels for the chart
    const char *labels[] = {"0", "1", "2", "3", "4", "5", "6", "7", "8"};

    // Create a XYChart object of size 600 x 300 pixels, with a pale red (ffdddd) background, black
    // border, 1 pixel 3D border effect and rounded corners.
    XYChart *c = new XYChart(600, 300, 0xffdddd, 0x000000, 1);
    c->setRoundedFrame();

    // Set the plotarea at (55, 58) and of size 520 x 195 pixels, with white (ffffff) background.
    // Set horizontal and vertical grid lines to grey (cccccc).
    c->setPlotArea(55, 58, 520, 195, 0xffffff, -1, -1, 0xcccccc, 0xcccccc);

    // Add a legend box at (55, 32) (top of the chart) with horizontal layout. Use 9pt Arial Bold
    // font. Set the background and border color to Transparent.
    c->addLegend(55, 32, false, "arialbd.ttf", 9)->setBackground(Chart::Transparent);

    // Add a title box to the chart using 15pt Times Bold Italic font. The title is in CDML and
    // includes embedded images for highlight. The text is white (ffffff) on a dark red (880000)
    // background, with soft lighting effect from the right side.
    c->addTitle(
        "<*block,valign=absmiddle*><*img=star.png*><*img=star.png*> Performance Enhancer "
        "<*img=star.png*><*img=star.png*><*/*>", "timesbi.ttf", 15, 0xffffff)->setBackground(
        0x880000, -1, Chart::softLighting(Chart::Right));

    // Add a title to the y axis
    c->yAxis()->setTitle("Energy Concentration (KJ per liter)");

    // Set the labels on the x axis
    c->xAxis()->setLabels(StringArray(labels, (int)(sizeof(labels) / sizeof(labels[0]))));

    // Add a title to the x axis using CMDL
    c->xAxis()->setTitle("<*block,valign=absmiddle*><*img=clock.png*>  Elapsed Time (hour)<*/*>");

    // Set the axes width to 2 pixels
    c->xAxis()->setWidth(2);
    c->yAxis()->setWidth(2);

    // Add a spline layer to the chart
    SplineLayer *layer = c->addSplineLayer();

    // Set the default line width to 2 pixels
    layer->setLineWidth(2);

    // Add a data set to the spline layer, using blue (0000c0) as the line color, with yellow
    // (ffff00) circle symbols.
    layer->addDataSet(DoubleArray(data1, (int)(sizeof(data1) / sizeof(data1[0]))), 0x0000c0,
        "Target Group")->setDataSymbol(Chart::CircleSymbol, 9, 0xffff00);

    // Add a data set to the spline layer, using brown (982810) as the line color, with pink
    // (f040f0) diamond symbols.
    layer->addDataSet(DoubleArray(data0, (int)(sizeof(data0) / sizeof(data0[0]))), 0x982810,
        "Control Group")->setDataSymbol(Chart::DiamondSymbol, 11, 0xf040f0);

    // Add a custom CDML text at the bottom right of the plot area as the logo
    c->addText(575, 250,
        "<*block,valign=absmiddle*><*img=small_molecule.png*> <*block*>"
        "<*font=timesbi.ttf,size=10,color=804040*>Molecular\nEngineering<*/*>")->setAlignment(
        Chart::BottomRight);

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

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