How Can i Load data from file.ecg and plot it ?

[ahmed ali]

thanks a lot for your help
but when i use this code i have some errors
i am using GUI application
can you help me to fix this?. sorry for annoying you but i am a beginner ... thanks in advance

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include<QFile>
#include<QtCore>
#include<QtGui>
#include<QTextStream>
 
MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    ui->label->setText("Hello User :)");
 
}
 
MainWindow::~MainWindow()
{
    delete ui;
}
 
void MainWindow::on_pushButton_clicked()
{
    QFile file("C:/ahmad/ecg test/tst.txt");
    if(!file.open( QFile::ReadOnly | QFile::Text))
    {
        ui->label->setText(" OOP : File Cant be Opened");
        return;
    }
    QStringList list;
    QTextStream in(&file);
    ui->label->setText("DONE : file opened");
    while (!in.atEnd())
    {
        list << in.readLine();
    }
   file.close();
data = new double[list.size()];
for(int i = 0; i< list.size(); i++)
    {
    data[i] = list[i].toDouble();
    }
dataSize = list.size();
}

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include<QFile>
#include<QtCore>
#include<QtGui>
#include<QTextStream>

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    ui->label->setText("Hello User :)");

}

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

void MainWindow::on_pushButton_clicked()
{
    QFile file("C:/ahmad/ecg test/tst.txt");
    if(!file.open( QFile::ReadOnly | QFile::Text))
    {
        ui->label->setText(" OOP : File Cant be Opened");
        return;
    }
    QStringList list;
    QTextStream in(&file);
    ui->label->setText("DONE : file opened");
    while (!in.atEnd())
    {
        list << in.readLine();
    }
   file.close();
data = new double[list.size()];
for(int i = 0; i< list.size(); i++)
    {
    data[i] = list[i].toDouble();
    }
dataSize = list.size();
}

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and the errors are:
C:\examples\Plot-build-desktop-Qt_4_8_0_for_Desktop_-_MSVC2010__Qt_SDK__Debug\..\..\Examples\Plot\mainw indow.cpp:38: error: C2248: 'QWidget::data' : cannot access private member declared in class 'QWidget'
C:\examples\Plot-build-desktop-Qt_4_8_0_for_Desktop_-_MSVC2010__Qt_SDK__Debug\..\..\Examples\Plot\mainw indow.cpp:38: error: C2440: '=' : cannot convert from 'double *' to 'QWidgetData *'
Types pointed to are unrelated; conversion requires reinterpret_cast, C-style cast or function-style cast
C:\examples\Plot-build-desktop-Qt_4_8_0_for_Desktop_-_MSVC2010__Qt_SDK__Debug\..\..\Examples\Plot\mainw indow.cpp:41: error: C2248: 'QWidget::data' : cannot access private member declared in class 'QWidget'
C:\examples\Plot-build-desktop-Qt_4_8_0_for_Desktop_-_MSVC2010__Qt_SDK__Debug\..\..\Examples\Plot\mainw indow.cpp:41: error: C2679: binary '=' : no operator found which takes a right-hand operand of type 'double' (or there is no acceptable conversion)
C:\QtSDK\Desktop\Qt\4.8.0\msvc2010\include\QtGui/qwidget.h(143): could be 'QWidgetData &QWidgetData::operator =(const QWidgetData &)'
while trying to match the argument list '(QWidgetData, double)'
C:\examples\Plot-build-desktop-Qt_4_8_0_for_Desktop_-_MSVC2010__Qt_SDK__Debug\..\..\Examples\Plot\mainw indow.cpp:43: error: C2065: 'dataSize' : undeclared identifier