public void start(Stage stage) {

    stage.show();

    initial(stage);

    eventHandler();

    loadData();

    drawGraph();


}

public void start(Stage stage) {

    stage.show();

    initial(stage);

    eventHandler();

    while(true){
        loadData();

        drawGraph();
    }

}

private void loadData() {
    dataListTHz.clear();

    DataInfo data = TestData.generateData();

    int numData = data.numData;
    for (int i = 0; i < numData; i++) {
        double freq = data.freqArr.get(i);
        double pwr = data.pwrArr.get(i);
        dataListTHz.add(new XYChart.Data(freq, pwr));
    }
    seriesTHz.getData().addAll(dataListTHz);


}

private void drawGraph() {

    lineChart.getData().removeAll(seriesTHz);

    lineChart.getData().addAll(seriesTHz);

}