Steema Central

Code: Select all

Public Class Form1
    Private m_XValues1 As New List(Of Double)
    Private m_YValues1 As New List(Of Double)
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles Me.Load

        GetData()

        TChart1.Aspect.View3D = False
        TChart1.Legend.Visible = False
        Dim points As New Steema.TeeChart.Styles.Points()
        TChart1.Series.Add(points)
        Dim fastLine As New Steema.TeeChart.Styles.FastLine()
        TChart1.Series.Add(fastLine)

        Dim downSampling As New Steema.TeeChart.Functions.DownSampling(TChart1.Chart)
        points.Add(m_XValues1.ToArray, m_YValues1.ToArray)
        points.Active = False

        downSampling.DisplayedPointCount = 5000
        downSampling.Method = Steema.TeeChart.Functions.DownSamplingMethod.MinMaxFirstLastNull
        fastLine.TreatNulls = Steema.TeeChart.Styles.TreatNullsStyle.DoNotPaint
        fastLine.DataSource = points
        fastLine.Function = downSampling

    End Sub

    Private Sub GetData()
        Dim csv As String = "C:\Users\Public\Documents\downsample.csv"
        Using tfp As New FileIO.TextFieldParser(csv)
            tfp.SetDelimiters(","c)
            tfp.TextFieldType = FileIO.FieldType.Delimited

            Do Until tfp.EndOfData
                Dim fields() As String = tfp.ReadFields
                m_XValues1.Add(Double.Parse(fields(0)))
                m_YValues1.Add(Double.Parse(fields(1)))
            Loop
        End Using
    End Sub

    Private Sub TChart1_UndoneZoom(sender As Object, e As EventArgs) Handles TChart1.UndoneZoom
        TChart1(1).CheckDataSource()
    End Sub

    Private Sub TChart1_Zoomed(sender As Object, e As EventArgs) Handles TChart1.Zoomed
        TChart1(1).CheckDataSource()
    End Sub
End Class

Code: Select all

private void tChart1_Zoomed(object sender, EventArgs e)
{
  if (tChart1.Axes.Bottom.Maximum - tChart1.Axes.Bottom.Minimum < 5000)
		downSampling1.DisplayedPointCount = 0;
		line2.CheckDataSource();
}