美国新冠病毒确诊人数统计及预测

 ui->setupUi(this);

    m_girdLayoutChart = new QGridLayout(this);

    m_confirmSeries = new QLineSeries();
    m_confirmSeries->setName(tr("确诊"));
    m_confirmSeries->setPen(QPen(Qt::red, 3));

    m_mathFunction = new QLineSeries;
    m_mathFunction->setName(tr("函数模型"));
    m_mathFunction->setPen(QPen(Qt::green, 3));

    m_increaseConfirmSeries = new QLineSeries();
    m_increaseConfirmSeries->setName(tr("新增确诊"));
    m_increaseConfirmSeries->setPen(QPen(Qt::blue, 3));


    Document xlsxR("E:\\MyQtProject\\drawFunctionImage\\USA2019-nCov\\2019USA-nCov.xlsx");

    if ( xlsxR.load() ) // load excel file
    {
        for(int i=0; i<27;i++)
        {
            m_mathFunction->append(i+1, pow((i+1),3.7)+ 700*i );  
   //我自己瞎写的函数模型，指数函数后期太快，幂函数操作一下效果还好

            int confirmRow = i + 3; int confirmCol =  3;     //确诊人数
            int increaseConfirmRow = i + 3; int increaseConfirmCol =  4;  //新增确诊

            Cell* confirmCell = xlsxR.cellAt(confirmRow, confirmCol); // get cell pointer.
            Cell* increaseConfirmCell = xlsxR.cellAt(increaseConfirmRow, increaseConfirmCol);
            if ( confirmCell != nullptr )
            {
                QVariant confirmVar = confirmCell->readValue(); // read cell value (number(double), QDateTime, QString ...)
                QVariant increaseConfirmVar = increaseConfirmCell->readValue();

                m_confirmSeries->append(i+1, confirmVar.toInt());
                m_increaseConfirmSeries->append(i+1, increaseConfirmVar.toInt());
            }
            else
            {
                qDebug() << "[debug] cell is not set.";
            }
        }
    }
    else
    {
        qDebug() << "[debug][error] failed to load xlsx file.";
    }

    QChart *chart = new QChart();
//    chart->legend()->hide();
    chart->addSeries(m_confirmSeries);
    chart->addSeries(m_increaseConfirmSeries);
    chart->addSeries(m_mathFunction);
    chart->createDefaultAxes();
    chart->setTitle("2019USA-nCov");

    QChartView *chartView = new QChartView(chart);
    chartView->setRenderHint(QPainter::Antialiasing);

    m_girdLayoutChart->addWidget(chartView);