ChartDirector 6.0 (C++ Edition)

Contour Chart




This example demonstrates creating a contour chart.

Source Code Listing

[The following code is available in "cppdemo/contour". 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"
#include <math.h>

int main(int argc, char *argv[])
{
    // The x and y coordinates of the grid
    double dataX[] = {-10, -9, -8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
    double dataY[] = {-10, -9, -8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10};

    // The values at the grid points. In this example, we will compute the values using the formula
    // z = x * sin(y) + y * sin(x).
    double dataZ[(int)(sizeof(dataX) / sizeof(dataX[0])) * (int)(sizeof(dataY) / sizeof(dataY[0]))];
    for(int yIndex = 0; yIndex < (int)(sizeof(dataY) / sizeof(dataY[0])); ++yIndex) {
        double y = dataY[yIndex];
        for(int xIndex = 0; xIndex < (int)(sizeof(dataX) / sizeof(dataX[0])); ++xIndex) {
            double x = dataX[xIndex];
            dataZ[yIndex * (int)(sizeof(dataX) / sizeof(dataX[0])) + xIndex] = x * sin(y) + y * sin(
                x);
        }
    }

    // Create a XYChart object of size 600 x 500 pixels
    XYChart *c = new XYChart(600, 500);

    // Add a title to the chart using 15 points Arial Bold Italic font
    c->addTitle("z = x * sin(y) + y * sin(x)      ", "arialbi.ttf", 15);

    // Set the plotarea at (75, 40) and of size 400 x 400 pixels. Use semi-transparent black
    // (80000000) dotted lines for both horizontal and vertical grid lines
    c->setPlotArea(75, 40, 400, 400, -1, -1, -1, c->dashLineColor(0x80000000, Chart::DotLine), -1);

    // Set x-axis and y-axis title using 12 points Arial Bold Italic font
    c->xAxis()->setTitle("X-Axis Title Place Holder", "arialbi.ttf", 12);
    c->yAxis()->setTitle("Y-Axis Title Place Holder", "arialbi.ttf", 12);

    // Set x-axis and y-axis labels to use Arial Bold font
    c->xAxis()->setLabelStyle("arialbd.ttf");
    c->yAxis()->setLabelStyle("arialbd.ttf");

    // When auto-scaling, use tick spacing of 40 pixels as a guideline
    c->yAxis()->setTickDensity(40);
    c->xAxis()->setTickDensity(40);

    // Add a contour layer using the given data
    ContourLayer *layer = c->addContourLayer(DoubleArray(dataX, (int)(sizeof(dataX) / sizeof(dataX[0
        ]))), DoubleArray(dataY, (int)(sizeof(dataY) / sizeof(dataY[0]))), DoubleArray(dataZ, (int)(
        sizeof(dataZ) / sizeof(dataZ[0]))));

    // Move the grid lines in front of the contour layer
    c->getPlotArea()->moveGridBefore(layer);

    // Add a color axis (the legend) in which the top left corner is anchored at (505, 40). Set the
    // length to 400 pixels and the labels on the right side.
    ColorAxis *cAxis = layer->setColorAxis(505, 40, Chart::TopLeft, 400, Chart::Right);

    // Add a title to the color axis using 12 points Arial Bold Italic font
    cAxis->setTitle("Color Legend Title Place Holder", "arialbi.ttf", 12);

    // Set color axis labels to use Arial Bold font
    cAxis->setLabelStyle("arialbd.ttf");

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

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