We are planning to implement new financial platform. There are requirements for realtime processing. Almost all reqs are based on time series. The type of charts are candlesticks, HiLo renderers. About UI control is necessary to move dynamically and fast in windowed time range, to see detailed structure of prices. The last important req is possibility to add lines to the chart for visualization entries and exits of trades. There can be a thousands these objects which can be added to the chart for visualization. Is it possible to used your library for it? Or do you recommend to start from javafx directly? Thanks for your advice.

Hi again,

I continue to enjoy building something up with chart-fx. One thing that has bugged me recently are the auto-generated names for datasets created from some computation, in particular things like DataSetMath. They are very informative, but a lot of them directly stringify double values such as interval bounds. Because of this, the names quickly become unwieldy to show to humans:

I have already written a formatter that is used for axis labels/ticks, indicators, hover info, info about measurements and so on. My trouble is in applying this format to the names of the mentioned datasets. If I am not missing something, at the moment I'd have to either duplicate and adapt the naming logic to change the series' names when they are calculated, or try to parse out any numeric values from the names, re-format them and put the name back together when I display it. Both of these are theoretically possible, but are also time-consuming and don't sound like the best solutions.

Ideally, I would want DataSetMath and MultiDimDataSetMath to use a configurable formatter for numbers in the names they assign. They could hold a default "identity" StringConverter< Number > that matches the current behaviour (or maybe uses a default NumberFormat / DecimalFormat like is used in other places) and expose a method to change this converter to a user-supplied one.

Do you think this would be a reasonable addition? Cheers, Domenic

Hi Dears, First of all I want to thank you again for this amazing work!

Here, I'm trying to draw the xAxis from the "Max" to the "Min" values. I'm not sure, how can I do it easily?

Thanks a lot

Background

First of all, thanks for writing a JavaFX charting library. I've been using JChart2D for what seems like forever, and I can't wait to finally get rid of the last remaining Swing parts.

I've been working on an application that visualizes streaming sensor/measurement data in real-time. One of the features is a way for non-programmers to create custom charts via XML files where they can specify equations as well as things like default ranges, colors, styles, and so on. For example

<chart title="GYROSCOPE" min_range="-3" max_range="+3" range_policy="expanding">
    <trace label="gyroX" units="rad/s" color="red" style="solid" value="fbk.gyroX" />
    <trace label="gyroY" units="rad/s" color="green" style="solid" value="fbk.gyroY" />
    <trace label="gyroZ" units="rad/s" color="blue" style="solid" value="fbk.gyroZ" />
</chart>

and

<chart title="LATENCY" min_range="0" max_range="0.5" range_policy="expanding">
    <trace label="Round Trip Time (RTT)" units="ms" color="black" style="points" value="(fbk.pcRxTime - fbk.pcTxTime)*1E3" />
    <trace label="Hardware Response Time" units="ms" color="blue" style="points" value="(fbk.hwTxTime - fbk.hwRxTime)*1E3" />
    <trace label="Transmit Time dt" units="ms" color="green" style="points" value="isNaN(prevFbk.pcTxTime) ? 0 : (fbk.pcTxTime - prevFbk.pcTxTime)*1E3" />
</chart>

Unfortunately, I keep running into various basic issues when trying to port the charts over to chart-fx.

Questions / Problems

• We typically want to show the last N measurements, or the last (up to N) measurements within some time period. It'd be nice to have a LimitedCircularDoubleDataSet. It sounds very much like #8, so I'd second that as a feature request. Once I'm more familiar with this library I may be able to contribute something.

• How can I dynamically set colors for individual datasets? The only reference I've found was in RollingBufferLegacyExample via setting the chart style for .default-color{index}.chart-series-line{...}. Unfortunately, doing that doesn't seem to have any effect.

• Similarly, how can I selectively change the style of individual datasets? e.g. render one dataset with only markers (e.g. MATLAB's ., o, x), and another dataset as a solid/dashed/dotted line without markers (e.g. MATLAB's -, --, :). DataSet::getDataStyleMap::put seems to apply only to individual points

• How can I render a dashed line? I found some usages of DashPatternStyle in the GridRenderer, but found nothing about using it for individual datasets.

• What JDK/JFX version were you using for the performance comparisons in your paper? In particular, I'd be interested to know whether the numbers are before or after the Marlin renderer changes.

Thanks!

Edit: cleaned up the questions a bit

Hi! Thank you for your work on ChartFX.

I'm having an issue with redrawing a chart after updating its datasets. I update datasets as follows:

public void update(List<DataPoint> dataPoints) {
    renderer.getDatasets().clear();
    DefaultDataSet dataSet = new DefaultDataSet("DataSet");
    for (DataPoint dataPoint : dataPoints) {
            double retTime = dataPoint.getRetTime();
            double intensity = dataPoint.getIntensity();
            dataSet.add(retTime, intensity);
    }
    renderer.getDatasets().add(dataSet);
}

where renderer is ErrorDataSetRenderer added to an XYChart.

When I call this function, sometimes I get a correct plot and sometimes I get a blank background. Here are a few examples:

I was able to solve this issue by calling chart.layout() after I update datasets, as follows:

public void update(List<DataPoint> dataPoints) {
    renderer.getDatasets().clear();
    DefaultDataSet dataSet = new DefaultDataSet("DataSet");
    for (DataPoint dataPoint : dataPoints) {
            double retTime = dataPoint.getRetTime();
            double intensity = dataPoint.getIntensity();
            dataSet.add(retTime, intensity);
    }
    renderer.getDatasets().add(dataSet);

    chart.layout()
}

The latter code works and displays all plots correctly whenever the legend is visible (i.e. chart.setLegendVisible(true)). However, when the legend isn't visible, then the plots are still sometimes displayed and sometimes not. I want my users to be able to hide the legend, so I guess I need another solution for my problem.

Maybe, I just don't call a correct function to update charts. What is the recommended ways to redraw plots after updating datasets?

Hi,

I would like to thank everyone who worked hard on Chart-Fx.

I am using the ContourChart to draw like one million point, here is an image of what I draw:

Note that each time I get more points and redraw them after clearing the chart using getDatasets().clear().

When I switch between views, it seems as if the points data are maintained in memory. I'm not really sure if there is something I should do since I'm relying on the garbage collector to do this for me which doesn't seem to do anything.

Sorry, i don't know where to turn with my question so I'll post it here.

Firstly, i really enjoy working with chart-fx. It is by far the best charting lib for my use case that I have ever come across! Thanks for your effort!

I am currently writing an application which has a dark theme and I was not yet able to completely figure out how to style chart-fx so that it renders nicely on a dark background. I am currently trying to find how to set the color of label of the axis (i suppose it is the axis tick label?) but what ever I do, it remains black (see attached screenshot).

I have tried setting it via css

.axis-label {
     /*this sets the axis label ("value [m/s²]") correctly*/
    -fx-fill: lightgrey;

    /*these two don't seem to work*/
    -fx-text-fill: yellow;
    -fx-tick-label-fill: red
}

or via the Axis using setTickLabelFill = Color.CYAN;

The result is always a chart with black tick labels:

I also checked the JavaFX Documentation for Styling Charts with CSS as well as the JavaFX CSS Reference Guide but found nothing that helped me.

I would appreciate it very much if you can help me with this styling issue or direct me to a place where i can find more help! Thanks!

Hi everyone. I have a memory problem with the charts. the chart-fx threads are not getting terminated when I close the charts view, thus the allocated stack memory by the threads is not getting released.

this is a scenario of my case: 1 - I open a new Scene with two bar charts, two contour charts with no data on them.

charts:

memory:

2- add data to the charts.

charts:

memory:

3- move to other views by changing the parent of the current scene memory:

the chart-fx threads still occupy the memory.

4- open the charts view again with empty charts and start reading data ( the same data as the first time) charts:

memory:

I've tried some solutions but nothing worked for me. I don't have a problem with heap memory.

After some time i got back to working on my UI Project. :)

I added the de.gsi.chart.plugins.CrosshairIndicator plugin to a chart. The lines (crosshairPath) works as expected. But the label (coordinatesLabel) is not updated on mouse-move but only when i zoom in/out of the chart.

Best see a short video as demonstration: You see at the beginning it does not show the text at all, but only after i zoomed out, it rendered the label. But then it got stuck on one value until the next zoooming.

I checked to verify that the method private void updateLabel(final MouseEvent event, final Bounds plotAreaBounds) inCrosshairIndicator is actually invoked and also calls coordinatesLabel.setText() with the correct updated string. I have no clue why it is not rendered on the graph.

I tried removing the Zoomer-Plugin to see if that may block it, but it did not work.

I would appreciate if you could help me.

I am using

• JDK: OpenJDK 14.0.1
• JavaFX 13.0.2
• chart-fx: 11.1.5
• OS: Linux 5.7.12-arch1-1

Hello, everybody! I try to make oscilloscope using chart-fx. I use FloatDataSet to display oscilloscope data. I get data blocks from sound cart and send send it to display a chart. When I run my program I often get an error:

Exception in thread "JavaFX Application Thread" java.lang.StackOverflowError
	at de.gsi.dataset.spi.AbstractDataSet.binarySearch(AbstractDataSet.java:133)
	at de.gsi.dataset.spi.AbstractDataSet.binarySearch(AbstractDataSet.java:133)
	at de.gsi.dataset.spi.AbstractDataSet.binarySearch(AbstractDataSet.java:133)
	at de.gsi.dataset.spi.AbstractDataSet.binarySearch(AbstractDataSet.java:133)
	at de.gsi.dataset.spi.AbstractDataSet.binarySearch(AbstractDataSet.java:133)
	at de.gsi.dataset.spi.AbstractDataSet.binarySearch(AbstractDataSet.java:133) etc.

How can I fix it? Help me please.

Hi, thanks for the great charting library.

Is there any way to change the color scheme to the one from default JavaFX charts? chart.css doesn't use the colors that I see on the screen and I see that ErrorDataSetRenderer uses static calls to DefaultRenderColorScheme, but doesn't seem to have a method to set another scheme. DefaultRenderColorScheme does have different color arrays as fields, but again, I see no way to change which one is used or to add my own. I'd also like to disable hatching and symbols and just draw the lines themselves. FillPattern seems to have "solid" as an option, but it's not used anywhere, as far as I can tell. Am I missing something?

As a side question: is there any way to break up the data inside one dataset? I'm getting series of independent readings from the same sensors over time and I don't want to create a bunch of new datasets for each one, as that would look confusing. So I want clear space to separate them, but by default the last point of the previous series and the first point of the new one would get connected, as if it's the same series (which makes sense of course, but it's not what I want). In vanilla JavaFX charts I could traverse the node path and replace LineTo with MoveTo, which was very cumbersome, but generally worked. What's the approach here?

java: cannot find symbol symbol: class MultiArrayDouble location: package io.fair_acc.dataset.spi.utils

• JavaFx version:
• ChartFx version: [master, 11.2.2, ...]

Describe the bug

chart.css lists CSS selectors for styling the grid lines, but overwriting them currently does not work.

.chart-major-vertical-lines .chart-major-grid-lines {
  /* use this to override v-specific settings */
}

.chart-major-horizontal-grid-lines .chart-major-grid-lines {
  /* use this to override h-specific settings */
}

This is because GridRenderer lives in a separate Scene with manual updates to applyCss, so it does not see any styles applied to the main chart. Applying styles directly to the renderer should work, but somehow that seems to have issues too.

Workaround

For now I made it work by adding the GridRenderer to an invisible/unmanaged group to an unused panel, e.g.,

public static <T extends Chart> T fixChartCss(T chart) {
    if (chart instanceof XYChart xy) { 
        var hiddenGroup = new Group(xy.getGridRenderer());
        hiddenGroup.setVisible(false);
        hiddenGroup.setManaged(false);
        xy.getToolBar().getChildren().add(hiddenGroup);
    }
    return chart;
}

Discussion

The approach with invisible lines seems to work well, but I think they should be part of the main scenegraph to avoid special casing and odd behavior. Do you think it would make sense to add a dedicated non-visible/unmanaged portion in Chart that exists only for CSS updates?

If so, how should the GridRenderer register to the chart? The quick hack would be to add it on render(chart), but it may make sense to register it in a similar manner as plugins.

The boolean expressions used in ErrorDataSetRenderer.drawBubbles are wrong and repeat/overlap so that only the first two braches ever match. Use conjunct clauses && to make distinct conditions for the branches.

Environment:

• ChartFx version: master
• attribution: IntelliJ

displaying live data from data sets with fluctuating size created a lot of GC pressure because the DoubleArrayCache required a new allocation almost every call to getArrayExact

adjusting the ErrorDataSetRenderer and related classes to call DoubleArrayCache.getArray (using best fit strategy) instead removes this overhead

the time spend in the cache easily took 90% of the render time in our case, because the cache list grews quite large

When I set DoubleDataSet style with strokeDashPattern like "strokeDashPattern=5,5,5,5;" and add dataSet to chart ,the window become no response.

follow the code:

import de.gsi.chart.XYChart;
import de.gsi.chart.axes.spi.DefaultNumericAxis;
import de.gsi.dataset.spi.DoubleDataSet;
import javafx.application.Application;
import javafx.application.Platform;
import javafx.scene.Scene;
import javafx.stage.Stage;
import java.util.Random;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

public class DashSample extends Application {
    private ScheduledExecutorService scheduledExecutorService = Executors.newScheduledThreadPool(1);

    @Override
    public void start(Stage primaryStage) throws Exception {
        final XYChart chart = new XYChart(new DefaultNumericAxis(), new DefaultNumericAxis());
        chart.setAnimated(false);
        chart.setLegendVisible(false);

        final Scene scene = new Scene(chart, 600, 400);
        primaryStage.setTitle(this.getClass().getSimpleName());
        primaryStage.setScene(scene);
        primaryStage.setOnCloseRequest(evt -> Platform.exit());
        primaryStage.show();

        scheduledExecutorService.schedule(() -> {
            Platform.runLater(() -> {
                Random random = new Random();
                final DoubleDataSet dataSet = new DoubleDataSet("myData");
                for (int i = 0; i < 10; i++) {
                    dataSet.add(random.nextDouble(), random.nextDouble());
                }
                dataSet.setStyle("strokeDashPattern=5,5,5,5;");
                chart.getDatasets().add(dataSet);
            });
        }, 3, TimeUnit.SECONDS);
    }
}

Environment:

• OS: window 7
• Java version: jdk1.8.0_311
• ChartFx version: 8.1.5

When using the contour plots, there seems to be a vertical axis bug when enlarging vertically (which works fine), and then when shrinking back down. To easily reproduce, just try the following with your WaterfallPerformanceSample in your chart.samples.

At first, everything is fine plot/functionality wise when launched. But then vertically increase height of window, then go back down to default size. You'll lose the x-axis. I would expect that the contour chart stretches/shrinks vertically and fits according to the window size, similar to all other chart types, as well as horizontal stretching/shrinking works fine as expected.

Thanks for your help in advance. Fantastic library nonetheless!

Environment:

• OS: [e.g. Ubuntu 20.04]
• Java version: openjdk 11
• JavaFx version: 11
• ChartFx version: [master, 11.2.2, ...]