具有65000个数据点的JavaFX LineChart的性能问题 [英] Performance issue with JavaFX LineChart with 65000 data points

问题描述

JavaFX花费15分钟来构建描述的LineChart，这对我的任务不起作用.

It takes JavaFX 15 minutes to build described LineChart which doesn't work for my task.

使用良好的旧版Swing和jFreeChart进行类似的实现需要花费1.5秒来构建图表.

Similar implementation using good old Swing and jFreeChart takes 1.5 seconds to build chart.

但是我仍然想实现一个JavaFX.

But I would still like to implement a JavaFX one.

这是我的代码:

public class FXMLController implements Initializable {

@FXML
private Label statusbar;
@FXML
public LineChart lineChart;
@FXML
public Button connect;
@FXML
public MenuItem options;
@FXML
public NumberAxis xAxis;
@FXML
NumberAxis yAxis;

@FXML
private void connect(ActionEvent event) {

}
public static FileChooser fileChooser = new FileChooser();
public static String path;
public static XYChart.Series<Integer, Integer> dataSeries = new XYChart.Series<Integer, Integer>();
public static int y = 0;
public static XYChart.Data<Integer, Integer> data;


@FXML
private void open(ActionEvent event) {
    fileChooser.setTitle("Open Resource File");
    fileChooser.getExtensionFilters().addAll(
            new ExtensionFilter("Text Files", "*.txt"),
            new ExtensionFilter("Image Files", "*.png", "*.jpg", "*.gif"),
            new ExtensionFilter("Audio Files", "*.wav", "*.mp3", "*.aac"),
            new ExtensionFilter("All Files", "*.*"));
    File selectedFile = fileChooser.showOpenDialog(new Stage());
    if (selectedFile != null) {
        path = selectedFile.getAbsolutePath();
        System.out.println(path);
        try {
            ReadingFromFile.readFile(path);

        } catch (IOException ex) {
            Logger.getLogger(FXMLController.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

}

@FXML
private void close(ActionEvent event) {

}

@FXML
private void getconnect(ActionEvent event) {

}

@Override
public void initialize(URL url, ResourceBundle rb) {
    xAxis.setLabel("Tick");
    xAxis.setTickUnit(100);
    yAxis.setLabel("Signal");
    xAxis.setForceZeroInRange(false);
    lineChart.setLegendVisible(false);
    lineChart.setCreateSymbols(false);
    lineChart.setAnimated(false);
    lineChart.getData().add(dataSeries);
  }
}

并从文件中读取:

public class ReadingFromFile extends FXMLController {

public static String s = null;
public static String[] str;
public static int parseInt;

public static void readFile(String filename)
        throws IOException {

    BufferedReader br = new BufferedReader(new FileReader(filename));
    try {
        StringBuilder sb = new StringBuilder();
        String line = br.readLine();

        while (line != null) {
            sb.append(line);
            sb.append(System.lineSeparator());
            line = br.readLine();

            System.out.println(line);
            try {
                str = line.split(" ");
                for (int i = 0; i < str.length; i = i + 2) {
                    s = str[i + 1] + str[i];
                    parseInt = Integer.parseInt(s, 16);
                    javafx.application.Platform.runLater(new Runnable() {
                        @Override
                        public void run() {

                            data = new XYChart.Data<Integer, Integer>(y, parseInt);
                            //data.setNode(new HoveredThresholdNode(0, second, ""));
                            dataSeries.getData().add(data);
                            y++;
                        }

                    });
                }
            } catch (java.lang.NullPointerException ex) {
                System.out.println("тут ноль!!!");

            }

        }

    } finally {

        br.close();
    }

}

}

推荐答案

我遇到了类似的问题，每隔几秒钟就会向LineChart添加100,000点.我们使用了 Ramer–Douglas–Peucker算法，这会减少用户不注意的直线上的点数.我在LGPL许可下的 JTS拓扑套件中找到了现成的实现.

I experienced a similar problem, adding 100,000 points to a LineChart every couple of seconds. We solved it using the Ramer–Douglas–Peucker algorithm, this reduces the number of points in the line without the user noticing. I found an ready-made implementation in the JTS topology suite under LGPL license.

这是我的测试代码.

public class ChartUpdate extends Application {

    public static void main(String[] args) {
        launch(args);
    }

    @Override
    public void start(Stage stage) {

        NumberAxis xAxis = new NumberAxis(0, 50_000, 5000);
        xAxis.setAutoRanging(false);
        NumberAxis yAxis = new NumberAxis(-1, 1, 25);
        yAxis.setAutoRanging(false);
        LineChart<Number, Number> graph = new LineChart<>(xAxis, yAxis);
        graph.setAnimated(false);
        graph.setCreateSymbols(false);
        graph.setLegendVisible(false);
        Series<Number, Number> series = new Series<>();
        stage.setScene(new Scene(graph));

        GeometryFactory gf = new GeometryFactory();

        long t0 = System.nanoTime();
        Coordinate[] coordinates = new Coordinate[100_000];
        for (int i = 0; i < coordinates.length; i++) {
            coordinates[i] = new Coordinate(i, Math.sin(Math.toRadians(i / 100)));
        }
        Geometry geom = new LineString(new CoordinateArraySequence(coordinates), gf);
        Geometry simplified = DouglasPeuckerSimplifier.simplify(geom, 0.00001);
        List<Data<Number, Number>> update = new ArrayList<Data<Number, Number>>();
        for (Coordinate each : simplified.getCoordinates()) {
            update.add(new Data<>(each.x, each.y));
        }
        long t1 = System.nanoTime();

        System.out.println(String.format("Reduces points from %d to %d in %.1f ms", coordinates.length, update.size(),
                (t1 - t0) / 1e6));
        ObservableList<Data<Number, Number>> list = FXCollections.observableArrayList(update);
        series.setData(list);
        graph.getData().add(series);

        stage.show();

    }
}

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