C++ QT自定义绘图不正确

我正试图从机翼的

CSV

文件中绘制图形。我能够将值存储在

QStringList

的数组中并绘制它。但是，在零值处有一个突然的跳跃。我在

qDebug

中看到了输出，它显示了正确的值。请帮忙。我想不出这个问题

这是我的代码：

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QFile>
#include <QTextStream>
#include <QString>
#include <QMessageBox>
#include <QDebug>

MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
    ui->setupUi(this);
}

MainWindow::~MainWindow()
{
    delete ui;
}

static void process_line(const QByteArray &)
{
}

static void process_line(const QString &)
{
}

void MainWindow::on_read_clicked()
{
    QStringList fileData[1000];
    QStringList list2;
    QString line,line1;
    QString filename="C:/Users/PRASHANT/Desktop/xf-e197-il-200000.csv";

    QFile file(filename);
    if(!file.exists())
    {
        qDebug() << "NO File"<<filename;
    }
    else
    {
        qDebug() << filename<<"Success";
    }

    ui->textBrowser->clear();

    int i = 0;
    if (file.open(QIODevice::ReadOnly | QIODevice::Text))
    {
        QTextStream stream(&file);
        QStringList list2;

        while (!stream.atEnd())
        {

            line = stream.readLine();
            d1 = line.indexOf("Alpha");

            list2 = line.split(',', QString::SkipEmptyParts);
            fileData[i]=list2;
            if(list2.contains("Alpha"))
            {
                start=i;
            }

            i++;
        }
    }

    file.close();


    // generate some data:
    QVector<double> x1(120), y1(120),y2(120),y3(120),y4(120); // initialize with entries 0..100

    for (int i=1; i<117; i++)
    {
      x1[i] = QString(fileData[start+i][0]).toDouble();
      y1[i] = QString(fileData[start+i][1]).toDouble();
      y2[i] = QString(fileData[start+i][2]).toDouble();
      y3[i] = QString(fileData[start+i][4]).toDouble();
      y4[i] = y1[i]/y2[i];
      qDebug() << x1[i] << y1[i];
    }

    // create graph and assign data to it:
    ui->Cl_apha->addGraph();
    ui->Cl_apha->graph(0)->setData(x1, y1);
    ui->CD_alpha->addGraph();
    ui->CD_alpha->graph(0)->setData(x1,y2);
    ui->CM_alpha->addGraph();
    ui->CM_alpha->graph(0)->setData(x1,y3);
    ui->CL_vs_CD->addGraph();
    ui->CL_vs_CD->graph(0)->setData(x1,y4);

    // give the axes some labels:
    ui->Cl_apha->xAxis->setLabel("\u03B1");
    ui->Cl_apha->yAxis->setLabel("CL");
    ui->CD_alpha->xAxis->setLabel("\u03B1");
    ui->CD_alpha->yAxis->setLabel("CD");
    ui->CM_alpha->xAxis->setLabel("\u03B1");
    ui->CM_alpha->yAxis->setLabel("CM");
    ui->CL_vs_CD->xAxis->setLabel("\u03B1");
    ui->CL_vs_CD->yAxis->setLabel("CL/CD");

    // set axes ranges, so we see all data:
    ui->Cl_apha->xAxis->setRange(-10, 15);
    ui->Cl_apha->yAxis->setRange(-1, 1.5);
    ui->CD_alpha->xAxis->setRange(-10, 15);
    ui->CD_alpha->yAxis->setRange(-0.05, 0.1);
    ui->CM_alpha->xAxis->setRange(-10, 15);
    ui->CM_alpha->yAxis->setRange(-0.2,0.05);
    ui->CL_vs_CD->xAxis->setRange(-10, 15);
    ui->CL_vs_CD->yAxis->setRange(-20, 85);
    ui->Cl_apha->replot();
    ui->CD_alpha->replot();
    ui->CM_alpha->replot();
    ui->CL_vs_CD->replot();
}

void MainWindow::on_write_clicked()
{
    QString fileName ="C:/Destination.txt";
    QFile file(fileName);
}

"C:/Users/PRASHANT/Desktop/xf-e197-il-200000.csv"  Success...
-10.75 -0.3896
-10.5 -0.4297
-10.25 -0.4338
-10 -0.4179
-9.75 -0.4017
-9.5 -0.405
-9.25 -0.4173
-9 -0.4406
-8.75 -0.4813
-8.5 -0.5118
-8.25 -0.5597
-8 -0.5294
-7.75 -0.5
-7.5 -0.4699
-7.25 -0.4375
-7 -0.4083
-6.75 -0.3814
-6.5 -0.3562
-6.25 -0.3319
-6 -0.3116
-5.75 -0.2891
-5.5 -0.2676
-5.25 -0.2467
-5 -0.2264
-4.75 -0.2038
-4.5 -0.181
-4.25 -0.1584
-4 -0.1349
-3.75 -0.11
-3.5 -0.0844
-3.25 -0.0586
-3 -0.0324
-2.75 -0.0067
-2.5 0.0197
-2.25 0.0458
-2 0.0721
-1.75 0.0989
-1.5 0.1245
-1.25 0.1508
-1 0.1775
-0.75 0.2026
-0.5 0.2282
-0.25 0.2542
0 0.2784
0.25 0.3054
0.5 0.3389
0.75 0.3777
1 0.4205
1.25 0.4694
1.5 0.5191
1.75 0.5702
2 0.5972
2.25 0.6155
2.5 0.6374
2.75 0.6609
3 0.6816
3.25 0.7056
3.5 0.7295
3.75 0.7518
4 0.7775
4.25 0.7995
4.5 0.8246
4.75 0.8482
5 0.8729
5.25 0.897
5.5 0.9219
5.75 0.9453
6 0.9716
6.25 0.9936
6.5 1.0172
6.75 1.0415
7 1.0643
7.25 1.0859
7.5 1.1067
7.75 1.1263
8 1.1452
8.25 1.1618
8.5 1.1748
8.75 1.1804
9 1.1795
9.25 1.1739
9.5 1.1679
9.75 1.1641
10 1.1629
10.25 1.1618
10.5 1.1609
10.75 1.159
11 1.1573
11.25 1.1548
11.5 1.1486
11.75 1.1425
12 1.1415
12.25 1.141
12.5 1.1366
12.75 1.1421
13 1.1466
13.25 1.1508
13.5 1.1543
13.75 1.1634
14 1.1718
14.25 1.18
14.5 1.1884
14.75 1.1949
15 1.1989
15.25 1.2009
15.5 1.1996
15.75 1.1953
16 1.1873
16.25 1.1764
16.5 1.1598
16.75 1.1414
17 1.1209
17.25 1.0971
17.5 1.0722
17.75 1.0455
18 1.0162

输出图

---

您的代码似乎很好，但对于零值与相关。文件中的toDouble（）函数存在无法从字符串转换为双值的值。
通过引用传递布尔变量和下面类似if-cluse的代码来检查此函数，以查找丢失的数据

bool ok = false;
double temp = QString(fileData[start+i][0]).toDouble(&ok);
if (ok == false)
{
    qDebug() << QString(fileData[start+i][0]);
}

bool ok=false；
double temp=QString（fileData[start+i][0]）。toDouble（&ok）；
如果（确定==错误）
{
输出的qDebug（）图像尝试按您生成的数据将数据设置为qCustomPlot，就像qCustomPlot的一个简单演示。我确信您在将数据转换为双精度时出错。