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1 vote
5k views

Hello

In Tutorial 06b – Realtime Updates, I want change the <s:SciChartSurface.XAxis> from <s:NumericAxis/> to <s:DateTimeAxis/> . I have tried a lot, but it still doesn’t work.

Could you please help me to do this work.

Thank you very much.

  • Zhi Zhang asked 8 months ago
  • last active 8 months ago
1 vote
7k views

Hi, I asked a question a few days ago. I will try to explain better what I meant.
I get data in real time and I only care about the Y values.
My problem is that I don’t want to move forward on the X axis – but stay on a defined range
(If I move forward on the X-axis and I want to follow the graph I drew, I must define:

XAxis.AutoRange = SciChart.Charting.Visuals.Axes.AutoRange.Always;

And this means that I won’t be able to zoom properly unless I stop receiving the data, which is unacceptable.
So unless there is a way to set AutoRange = Always and still enable good zoom (similar to ZoomExtentsY for the X-axis), I need an option to keep seeing the graph all the time – without having to set AutoRange = Always so I can zoom.
I think the solution is to create a fixed range on the X-axis that the data will only be displayed on but before I implement it myself, I want to know if there is a better or built-in way to do this.

Just to make sure I’m understood, I want it to behave like in the attached images (the X-axis stays in the same range and the graph “move” to the left whenever new points enter from the right:

1 vote
6k views

I get data in real time and I only care about the Y values.
I want to define a range of values on the X axis that will be fixed (but if I want I can change it from time to time)
For example: define that the range will be from 0 to 1000 and all the information that arrives will be displayed only in this range. And when I pass the 1000 points it will simply “push” the older points aside.
For example: the point located at X=2 will move to X=1, 1 will move to 0 and 0 will leave the graph…
During the program I want of course to give the user the possibility to change this range if he wants.
The optimal way for me was to define a range of the X axis and when I do Append(), add only Y values so that they enter the next place on the X axis in order…
Is there an option in the API to set this? If not, how is it recommended to do it?

0 votes
0 answers
7k views

Hi,

I am having an issue with the SciChart graphs. I have attached an image – SciChartIssue.png, here which shows the issue. Our SciChart graph contains 8 channels of dataseries for EEG / EMG signals. By default the first channel is selected. When we select/deselect additional channels, they start showing up on the graph accordingly. The issue happens when a channel is de-selected. i.e. when any channel is de-selected, we are clearing that particular channel dataseries, while the other series is being appended and rendered using SuspendUpdates(). But on the graph, the waveform tends to move towards the extreme end of the chart (as seen from the image attached). we were initially using version 5.4 of Scichart. but i later updated it to v6.3, but still have the same issue.
If you are aware or have come across such an issue, then I would appreciate any help or advice from you. Since this is a vast and secure project, I am not able to share the entire code with you at this moment. However, I have attached a xaml & .cs file used to render the graph, If it helps.

Thanks!

0 votes
12k views

Hey There.

I am new to sciChart and i am in ahurry to develop a realtime ECG App which takes data from Bluetooth. Ignore the harware part. Can anyone kindly prove me source code of realtime ecg monitoring or realtime linechart.

Thanx in advance

0 votes
11k views

I’ve been trying a few ways to get this to work now and I’m still struggling to get a catch-all solution.

My requirements are:
– self-scrolling real-time data series with a fixed-time range (regardless of the number of points)
– y axis should support either fixed or automatic visual range
– support rubber band zoom (and ideally mousewheel too) on both axes

The key problem is that the stock ticker example doesn’t have a fixed time width. The points are added to the chart, and the axis expands until it reaches capacity. It’s also relatively easy to use FifoCapacity (adding a lot of NaN points), but FifoCapacity works on number of points, which isn’t great when you have irregular updates. I’m happy with the chart not scrolling until a new update is received, but the range of the chart must be fixed (say, five minutes), regardless of the number of visible points on the chart.

My current solution involves deriving from XyDataSeries to duplicate the FifoCapacity behaviour for a fixed time:

   public class RealTimeXyDataSeries<T> : XyDataSeries<DateTime, T>
            where T : IComparable
{
    public TimeSpan _limit;

    public TimeSpan Limit
    {
        get { return _limit; }
        set
        {
            _limit = value;
            Update();
        }
    }

    public RealTimeXyDataSeries(TimeSpan limit)
    {
        Limit = limit;
    }

    public override void Append(DateTime x, T y)
    {
        base.Append(x, y);

        Update();
    }

    public void Update()
    {
        if ((DateTime)XMax == DateTime.MinValue) return;

        var c = 0;

        while (XValues[c] < (DateTime) XMax - Limit) c++;

        if (c <= 0) return;

        RemoveRange(0, c);
    }
}

That takes care of removing points, but doesn’t deal with the range issue. To deal with that, I have some code in my codebehind to set the XAxis VisibleRange on every update, which feels a bit nasty. I wanted to create a RealTimeDateTimeAxis, but none of the relevant functions are override/virtual.

I also took the implementation of RubberBandXyZoomModifierEx from the knowledge base, with some modifications to deal with Y-Axis zoom/reset based on it’s AutoRange setting. However, this involves setting the Y-Axis AutoRange state back to a saved value, and I keep seeing MouseModifierUp events after my DoubleClick events, which resets AutoRange back to Never.

It feels like I’m doing a lot of work in a lot of places to get this to work, and it’s resulting in complex code and buggy behaviours; I’m not comfortable handing this over to another engineer in the current state.

Is there a better way to do this?

  • Rick C asked 7 years ago
  • last active 7 years ago
1 vote
16k views

Hello,

I have been working with an application that plots real-time serial data using a FIFO buffer. I have started programming around the ECG-Monitor example as this is exactly what I am creating.

I have a device that broadcasts real-time ECG data via Bluetooth (HC-05), to be exact. I have paired the device and opened a SerialPort in my program to receive the data. My sampling rate is 256 Hz.

When I used a text file to simulate ECG data, it works perfectly well. However, when I use real-time data, there is a delay in charting that increases as the time increases. An easier way to understand this is, the chart continues plotting for a significant period of time even after I have switched off my hardware device.

I have then come to the conclusion that my data is being received at the rate that I want it to, but the plotting gets delayed at an increasing rate as the time increases.

I am currently using the Direct-X rendering type as this gives me a very smooth plot. I receive the data via SerialPort, write to an array and then to the FIFO buffer.

I’m attaching my code for the same.

namespace SciChart.Examples.Examples.SeeFeaturedApplication.ECGMonitor
{
    public class ECGMonitorViewModel : BaseViewModel
    {
    private Timer _timer;
    private IXyDataSeries<double, double> _series0;
    public static double[] _sourceData = new double[50000];
    private int _currentIndex = 0;
    private int _totalIndex = 0;
    private DoubleRange _yVisibleRange;
    private bool _isBeat;
    private int _heartRate;
    private bool _lastBeat;
    private DateTime _lastBeatTime;
    private ICommand _startCommand;
    private ICommand _stopCommand;
    private const double WindowSize = 5.0;
    private const int TimerInterval = 40;
    public static int counter = 0;
    public static SerialPort mySerialPort=new SerialPort("COM3",9600);

    public ECGMonitorViewModel()
    {
        mySerialPort.Open();
        ECGMonitorViewModel.mySerialPort.WriteLine("A");
        ECGMonitorViewModel.mySerialPort.WriteLine("F");

        _series0 = new XyDataSeries<double, double>() { FifoCapacity = 2460, AcceptsUnsortedData = true };

        YVisibleRange = new DoubleRange(-20, 500);
        _startCommand = new ActionCommand(OnExampleEnter);
        _stopCommand = new ActionCommand(OnExampleExit);
    }

    public ICommand StartCommand
    {
        get
        {
            return _startCommand;
        }
    }

    public ICommand StopCommand
    {
        get
        {
            return _stopCommand;
        }
    }

    public IXyDataSeries<double, double> EcgDataSeries
    {
        get
        {
            return _series0;
        }
        set
        {
            _series0 = value;
            OnPropertyChanged("EcgDataSeries");
        }
    }

    public DoubleRange YVisibleRange
    {
        get
        {
            return _yVisibleRange;
        }
        set
        {
            _yVisibleRange = value;
            OnPropertyChanged("YVisibleRange");
        }
    }

    public bool IsBeat
    {
        get
        {
            return _isBeat;
        }
        set
        {
            if (_isBeat != value)
            {
                _isBeat = value;
                OnPropertyChanged("IsBeat");
            }
        }
    }

    public int HeartRate
    {
        get { return _heartRate; }
        set
        {
            _heartRate = value;
            OnPropertyChanged("HeartRate");
        }
    }

    public void OnExampleExit()
    {
        if (_timer != null)
        {
            _timer.Stop();
            _timer.Elapsed -= TimerElapsed;
            _timer = null;
        }
    }

    public void OnExampleEnter()
    {
        _timer = new Timer(TimerInterval) { AutoReset = true };
        _timer.Elapsed += TimerElapsed;
        _timer.Start();
    }

    private void TimerElapsed(object sender, EventArgs e)
    {
        lock (this)
        {
            for (int i = 0; i < 10; i++)
            {
                AppendPoint(250);
            }

            if ((DateTime.Now - _lastBeatTime).TotalMilliseconds < 120) return;

            IsBeat = _series0.YValues[_series0.Count - 3] > 120 ||
                     _series0.YValues[_series0.Count - 5] > 120 ||
                     _series0.YValues[_series0.Count - 8] > 120;

            if (IsBeat && !_lastBeat)
            {
                HeartRate = (int)(60.0 / (DateTime.Now - _lastBeatTime).TotalSeconds);
                _lastBeatTime = DateTime.Now;
            }
        }
    }

    private void AppendPoint(double sampleRate)
    {
        if (_currentIndex >= _sourceData.Length)
        {
            _currentIndex = 0;
        }

        double voltage = _sourceData[_currentIndex];
        double time = _totalIndex / sampleRate %10;

        if(time==0.00)
        {
            voltage = double.NaN;
        }

        _series0.Append(time, voltage);

        _lastBeat = IsBeat;
        _currentIndex++;
        _totalIndex++;
    }

    public static void mySerialPort_DataReceived(object sender, SerialDataReceivedEventArgs e)
    {
        while (mySerialPort.BytesToRead > 0)
        {
            int b;
            b = mySerialPort.ReadByte();
            _sourceData[counter] = b;
            counter++;
        }
    }
}
}

namespace SciChart.Examples.Examples.SeeFeaturedApplication.ECGMonitor
{
    public partial class ECGMonitorView : UserControl
    {
        public ECGMonitorView()
        {
            InitializeComponent();
            ECGMonitorViewModel.mySerialPort.DataReceived += new SerialDataReceivedEventHandler(ECGMonitorViewModel.mySerialPort_DataReceived);
        }
    }
}

The xaml code is as follows,

<UserControl
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
         xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
         xmlns:local="clr-namespace:SciChart.Examples.Examples.SeeFeaturedApplication.ECGMonitor"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
         xmlns:s="http://schemas.abtsoftware.co.uk/scichart"
         xmlns:s3D="http://schemas.abtsoftware.co.uk/scichart3D" xmlns:XamlRasterizer="clr-namespace:SciChart.Drawing.XamlRasterizer;assembly=SciChart.Drawing" x:Class="SciChart.Examples.Examples.SeeFeaturedApplication.ECGMonitor.ECGMonitorView"
         d:DesignHeight="400"
         d:DesignWidth="600"
         mc:Ignorable="d">

<UserControl.Resources>

    <Style TargetType="{x:Type s:RenderSurfaceBase}">
        <Setter Property="Effect">
            <Setter.Value>
                <DropShadowEffect BlurRadius="5"
                                  ShadowDepth="0"
                                  Color="#FFB3E8F6" />
            </Setter.Value>
        </Setter>
    </Style>

    <local:BeatToScaleConverter x:Key="BeatToScaleConverter" />
</UserControl.Resources>

<i:Interaction.Triggers>
    <i:EventTrigger EventName="Loaded">
        <i:InvokeCommandAction Command="{Binding StartCommand}" />
    </i:EventTrigger>
    <i:EventTrigger EventName="Unoaded">
        <i:InvokeCommandAction Command="{Binding StopCommand}" />
    </i:EventTrigger>
</i:Interaction.Triggers>

<Grid>

    <s:SciChartSurface RenderPriority="Low" MaxFrameRate="25" AutoRangeOnStartup="False">

        <s:SciChartSurface.RenderableSeries>
            <s:FastLineRenderableSeries DataSeries="{Binding EcgDataSeries}"
                Stroke="#FFB3E8F6"                                      
                StrokeThickness="2" />
        </s:SciChartSurface.RenderableSeries>

        <s:SciChartSurface.YAxis>
            <s:NumericAxis AxisTitle="Voltage (mV)"
                DrawMinorGridLines="True"
                MaxAutoTicks="5"
                VisibleRange="{Binding YVisibleRange, Mode=TwoWay}" />
        </s:SciChartSurface.YAxis>

        <s:SciChartSurface.XAxis>
            <s:NumericAxis AxisTitle="Seconds (s)" TextFormatting="0.000s" VisibleRange="0, 10" AutoRange="Never"/>
        </s:SciChartSurface.XAxis>

        <s:SciChartSurface.RenderSurface>
            <s3D:Direct3D10RenderSurface/>
        </s:SciChartSurface.RenderSurface>

    </s:SciChartSurface>

    <StackPanel Margin="30,30" Orientation="Horizontal">
        <StackPanel.Effect>
            <DropShadowEffect BlurRadius="5"
                ShadowDepth="0"
                Color="#FFB3E8F6" />
        </StackPanel.Effect>

        <Grid HorizontalAlignment="Left" VerticalAlignment="Top">
            <Canvas x:Name="layer1"
                Width="20"
                Height="20"
                Margin="12,34,10,0">
                <Canvas.RenderTransform>
                    <ScaleTransform CenterX="-6"
                        CenterY="-6"
                        ScaleX="{Binding IsBeat, Converter={StaticResource BeatToScaleConverter}}"
                        ScaleY="{Binding IsBeat, Converter={StaticResource BeatToScaleConverter}}" />
                </Canvas.RenderTransform>
                <Path Data="m 0 0 c -4 -4 -8.866933 -10.79431 -10 -15 0 0 0 -5 5 -5 5 0 5 5 5 5 0 0 0 -5 5 -5 5 0 5.242535 4.02986 5 5 -1 4 -6 11 -10 15 z" Fill="#FFB0E6F4" />
            </Canvas>
        </Grid>

        <TextBlock HorizontalAlignment="Left"
            VerticalAlignment="Top"
            FontFamily="ArialBlack"
            FontSize="36"
            FontWeight="Bold"
            Foreground="#FFB0E6F4"
            Text="{Binding HeartRate}" />
        <TextBlock HorizontalAlignment="Left"
            VerticalAlignment="Top"
            FontFamily="ArialBlack"
            FontSize="36"
            FontWeight="Bold"
            Foreground="#FFB0E6F4"
            Text="BPM" />

    </StackPanel>

    <TextBlock Margin="5"
        HorizontalAlignment="Left"
        VerticalAlignment="Bottom"
        FontSize="9"
        FontStyle="Italic"
        Foreground="#FFB0E6F4"/>

</Grid>

I’ve attached pictures of what my program currently does. I have also attached a file with sample data in case anybody wants to test the program. I have also tried building in release mode and that doesn’t help, either.

The only issue is the delay in plotting of real-time data. Otherwise, the graphing and rendering is really smooth. As I am a complete beginner to this, can somebody help with me with what I might have done wrong?

Thanks a ton,

Jaivignesh Jayakumar

1 vote
17k views

I am considering applying server-side licensing for my javerScript application.

In the document below, there is a phrase “Our server-side licensing component is written in C++.”
(https://support-dev.scichart.com/index.php?/Knowledgebase/Article/View/17256/42/)

However, there is only asp.net sample code on the provided github.
(https://github.com/ABTSoftware/SciChart.JS.Examples/tree/master/Sandbox/demo-dotnet-server-licensing)

I wonder if there is a sample code implemented in C++ for server-side licensing.

Can you provide c++ sample code?
Also, are there any examples to run on Ubuntu?

Showing 8 results