ChartDirector 6.0 (C++ Edition)

Surface Chart (2)




This example extends the Surface Chart (1) example by adding surface grid and contour lines, and using alternative view angles and continuous coloring.

Source Code Listing

[The following code is available in "cppdemo/surface2". 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[] = {0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0};
    double dataY[] = {0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0};

    // The values at the grid points. In this example, we will compute the values using the formula
    // z = sin((x - 0.5) * 2 * pi) * sin((y - 0.5) * 2 * pi)
    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] - 0.5) * 2 * 3.1416;
        for(int xIndex = 0; xIndex < (int)(sizeof(dataX) / sizeof(dataX[0])); ++xIndex) {
            double x = (dataX[xIndex] - 0.5) * 2 * 3.1416;
            dataZ[yIndex * (int)(sizeof(dataX) / sizeof(dataX[0])) + xIndex] = sin(x) * sin(y);
        }
    }

    // Create a SurfaceChart object of size 720 x 540 pixels
    SurfaceChart *c = new SurfaceChart(720, 540);

    // Add a title to the chart using 20 points Times New Roman Italic font
    c->addTitle("Quantum Wave Function", "timesi.ttf", 20);

    // Set the center of the plot region at (360, 245), and set width x depth x height to 360 x 360
    // x 270 pixels
    c->setPlotRegion(360, 245, 360, 360, 270);

    // Set the elevation and rotation angles to 20 and 30 degrees
    c->setViewAngle(20, 30);

    // Set the data to use to plot the chart
    c->setData(DoubleArray(dataX, (int)(sizeof(dataX) / sizeof(dataX[0]))), DoubleArray(dataY,
        (int)(sizeof(dataY) / sizeof(dataY[0]))), DoubleArray(dataZ, (int)(sizeof(dataZ) / sizeof(
        dataZ[0]))));

    // Spline interpolate data to a 80 x 80 grid for a smooth surface
    c->setInterpolation(80, 80);

    // Set surface grid lines to semi-transparent black (dd000000)
    c->setSurfaceAxisGrid(0xdd000000);

    // Set contour lines to semi-transparent white (80ffffff)
    c->setContourColor(0x80ffffff);

    // Add a color axis (the legend) in which the left center is anchored at (645, 270). Set the
    // length to 200 pixels and the labels on the right side. Use smooth gradient coloring.
    c->setColorAxis(645, 270, Chart::Left, 200, Chart::Right)->setColorGradient();

    // Set the x, y and z axis titles using 10 points Arial Bold font
    c->xAxis()->setTitle("x/L(x)", "arialbd.ttf", 10);
    c->yAxis()->setTitle("y/L(y)", "arialbd.ttf", 10);
    c->zAxis()->setTitle("Wave Function Amplitude", "arialbd.ttf", 10);

    // Output the chart
    c->makeChart("surface2.jpg");

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