connect(&updateTimer, &QTimer::timeout, [this, chart, series, index](){
QVector<QPointF> points;
QVector<double> points_x;
QVector<double> points_y;
QList<QVariant> var = index.data(Qt::DisplayRole).toList();
for(int i = 0; i < var.size(); i++)
{
    points_x << var.at(i).toPointF().x();
    points_y << var.at(i).toPointF().y();
    points << var.at(i).toPointF();
}

series->replace(points);

double min_x = *std::min_element(points_x.constBegin(), points_x.constEnd());
double min_y = *std::min_element(points_y.constBegin(), points_y.constEnd());

double max_x = *std::max_element(points_x.constBegin(), points_x.constEnd());
double max_y = *std::max_element(points_y.constBegin(), points_y.constEnd());

chart->axisX()->setRange(min_x, max_x);
chart->axisY()->setRange(min_y, max_y);