Simulate EKG signal in RadChartView

Updated over 6 months ago

Environment

Product Version	Product	Author
2020.2.512	RadChartView for WinForms	Desislava Yordanova

Description

This tutorial demonstrates how to simulate an EKG signal in RadChartView.

Solution

RadChartView supports empty values in the series. In general, 'empty values' means missing Y value for a particular X value. This is appropriate for achieving blank parts within the chart. Using a timer, we will update the blank part in the line moving it forward.

Simulate an EKG signal

C#

Random rnd = new Random();
FastLineSeries series = new FastLineSeries();
Dictionary<string, double?> categoryValuePairs = new Dictionary<string, double?>();
public RadForm1()
{
    InitializeComponent();                  
    
    for (int i = 0; i < 100; i++)
    {
        CategoricalDataPoint point = new CategoricalDataPoint(rnd.Next(50, 100), i);
        series.DataPoints.Add(point); 
        categoryValuePairs.Add(i.ToString(),point.Value);
    }
    radChartView1.Series.Add(series);
    LinearAxis verticalAxis = series.VerticalAxis as LinearAxis;
    verticalAxis.Minimum = 50;
    verticalAxis.Maximum = 100;
    CategoricalAxis categoricalAxis = series.HorizontalAxis as CategoricalAxis; 
    categoricalAxis.LabelFitMode = AxisLabelFitMode.Rotate;
    categoricalAxis.MajorTickInterval = 5;
    this.timer1.Interval = 100;
}

private void radButton1_Click(object sender, EventArgs e)
{
    if (!this.timer1.Enabled)
    {
        this.timer1.Start();
    }
    else
    { 
        this.timer1.Stop();
    }
}

int cnt = 0;

private void timer1_Tick(object sender, EventArgs e)
{
    cnt++;
    if (cnt >= series.DataPoints.Count - 5)
    {
        cnt = 0;
    }
    CategoricalDataPoint point = null;
    for (int i = 0; i < series.DataPoints.Count; i++)
    {
        point = (CategoricalDataPoint)series.DataPoints[i];
        if (i >= cnt && i < cnt + 5)
        {
            point.Value = null;
        }
        else
        {
            point.Value = categoryValuePairs[point.Category.ToString()];
        }
    }
}
    

VB.NET

Private rnd As Random = New Random()
Private series As FastLineSeries = New FastLineSeries()
Private categoryValuePairs As Dictionary(Of String, Double?) = New Dictionary(Of String, Double?)()

Public Sub New()
    InitializeComponent()

    For i As Integer = 0 To 100 - 1
        Dim point As CategoricalDataPoint = New CategoricalDataPoint(rnd.[Next](50, 100), i)
        series.DataPoints.Add(point)
        categoryValuePairs.Add(i.ToString(), point.Value)
    Next

    RadChartView1.Series.Add(series)
    Dim verticalAxis As LinearAxis = TryCast(series.VerticalAxis, LinearAxis)
    verticalAxis.Minimum = 50
    verticalAxis.Maximum = 100
    Dim categoricalAxis As CategoricalAxis = TryCast(series.HorizontalAxis, CategoricalAxis)
    categoricalAxis.LabelFitMode = AxisLabelFitMode.Rotate
    categoricalAxis.MajorTickInterval = 5
    Me.Timer1.Interval = 100
End Sub

Private Sub RadButton1_Click(sender As Object, e As EventArgs) Handles RadButton1.Click
    If Not Me.Timer1.Enabled Then
        Me.Timer1.Start()
    Else
        Me.Timer1.[Stop]()
    End If
End Sub

Private cnt As Integer = 0

Private Sub timer1_Tick(ByVal sender As Object, ByVal e As EventArgs) Handles Timer1.Tick
    cnt += 1

    If cnt >= series.DataPoints.Count - 5 Then
        cnt = 0
    End If

    Dim point As CategoricalDataPoint = Nothing

    For i As Integer = 0 To series.DataPoints.Count - 1
        point = CType(series.DataPoints(i), CategoricalDataPoint)

        If i >= cnt AndAlso i < cnt + 5 Then
            point.Value = Nothing
        Else
            point.Value = categoryValuePairs(point.Category.ToString())
        End If
    Next
End Sub

    

See Also

• FastLine
• Null Values Support