ChartDirector是一個非常理想的圖表工具，它擁有廣泛的圖表類型、分層架構、實時互動的大數據表、普遍適應于各種應用程序以及支持PDF和SVG圖標等的優點。此系列連載旨在介紹ChartDirector的實用教程，供大家學習討論。

一、3D散點圖(1)

此示例演示了創建3D散點圖的基本步驟：

• 使用ThreeDScatterChart.ThreeDScatterChart創建ThreeDScatterChart對象。
• 使用ThreeDChart.setPlotRegion指定繪圖區域的位置和大小。
• 使用ThreeDScatterChart.addScatterGroup將散點圖組添加到圖表。在此示例中，符號顏色設置為SameAsMainColor，即顏色取決于z坐標。根據顏色軸（顏色圖例），可以使用ThreeDChart.colorAxis訪問顏色軸。
• 使用ThreeDChart.setColorAxis設置顏色軸（顏色圖例）的位置。
• 使用BaseChart.addTitle和Axis.setTitle添加圖表和軸標題。
• 使用圖表生成BaseChartmakeChart。

源代碼清單：

以下代碼可在“cppdemo / threedscatter”中找到。Mf版本的代碼可在“mfcdemo / mfcdemo”中找到（僅限Windows版本）。QT版本的代碼可在“qtdemo / qtdemo”中找到。

#include "chartdir.h"

int main(int argc, char *argv[])
{
    // The XYZ data for the 3D scatter chart as 3 random data series
    RanSeries *r = new RanSeries(0);
    DoubleArray xData = r->getSeries(100, 100, -10, 10);
    DoubleArray yData = r->getSeries(100, 0, 0, 20);
    DoubleArray zData = r->getSeries(100, 100, -10, 10);

    // Create a ThreeDScatterChart object of size 720 x 600 pixels
    ThreeDScatterChart *c = new ThreeDScatterChart(720, 600);

    // Add a title to the chart using 20 points Times New Roman Italic font
    c->addTitle("3D Scatter Chart (1)  ", "timesi.ttf", 20);

    // Set the center of the plot region at (350, 280), and set width x depth x height to 360 x 360
    // x 270 pixels
    c->setPlotRegion(350, 280, 360, 360, 270);

    // Add a scatter group to the chart using 11 pixels glass sphere symbols, in which the color
    // depends on the z value of the symbol
    c->addScatterGroup(xData, yData, zData, "", Chart::GlassSphere2Shape, 11, Chart::SameAsMainColor
        );

    // 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.
    c->setColorAxis(645, 270, Chart::Left, 200, Chart::Right);

    // Set the x, y and z axis titles using 10 points Arial Bold font
    c->xAxis()->setTitle("X-Axis Place Holder", "arialbd.ttf", 10);
    c->yAxis()->setTitle("Y-Axis Place Holder", "arialbd.ttf", 10);
    c->zAxis()->setTitle("Z-Axis Place Holder", "arialbd.ttf", 10);

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

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

二、3D散點圖(2)

此示例通過包含下劃線，使用替代視角和連續著色來擴展3D散點圖（1）示例。

下拉線是從數據點下降到XY平面的線。它們有助于可視化點的“高度”（z坐標），如果沒有太多數據點，則可能很有用。

• 使用ThreeDChart.setViewAngle設置備用視角。
• 使用ThreeDScatterGroup.setDropLine添加下拉線。
• 使用ColorAxis.setColorGradient配置連續著色。

源代碼清單：

以下代碼可在“cppdemo / threedscatter”中找到。Mf版本的代碼可在“mfcdemo / mfcdemo”中找到（僅限Windows版本）。QT版本的代碼可在“qtdemo / qtdemo”中找到。

#include "chartdir.h"

int main(int argc, char *argv[])
{
    // The XYZ data for the 3D scatter chart as 3 random data series
    RanSeries *r = new RanSeries(3);
    DoubleArray xData = r->getSeries(20, 100, -10, 10);
    DoubleArray yData = r->getSeries(20, 100, -10, 10);
    DoubleArray zData = r->getSeries(20, 100, -10, 10);

    // Create a ThreeDScatterChart object of size 720 x 520 pixels
    ThreeDScatterChart *c = new ThreeDScatterChart(720, 520);

    // Add a title to the chart using 20 points Times New Roman Italic font
    c->addTitle("3D Scatter Chart (2)  ", "timesi.ttf", 20);

    // Set the center of the plot region at (350, 240), and set width x depth x height to 360 x 360
    // x 270 pixels
    c->setPlotRegion(350, 240, 360, 360, 270);

    // Set the elevation and rotation angles to 15 and 30 degrees
    c->setViewAngle(15, 30);

    // Add a scatter group to the chart using 13 pixels glass sphere symbols, in which the color
    // depends on the z value of the symbol
    ThreeDScatterGroup *g = c->addScatterGroup(xData, yData, zData, "", Chart::GlassSphere2Shape,
        13, Chart::SameAsMainColor);

    // Add grey (888888) drop lines to the symbols
    g->setDropLine(0x888888);

    // Add a color axis (the legend) in which the left center is anchored at (645, 220). Set the
    // length to 200 pixels and the labels on the right side. Use smooth gradient coloring.
    c->setColorAxis(645, 220, Chart::Left, 200, Chart::Right)->setColorGradient();

    // Set the x, y and z axis titles using 10 points Arial Bold font
    c->xAxis()->setTitle("X-Axis Place Holder", "arialbd.ttf", 10);
    c->yAxis()->setTitle("Y-Axis Place Holder", "arialbd.ttf", 10);
    c->zAxis()->setTitle("Z-Axis Place Holder", "arialbd.ttf", 10);

    // Output the chart
    c->makeChart("threedscatter2.png");

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

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