Windows Forms Chart Log Scaling

Question

I'm trying to create a bubble chart with a logrithmic scale on the y axis. The data I'm plotting ranges from 0.1 to 1000. When the chart is plotted, the minimum value for the y-axis is always 1 and much of the data plots below the X axis. I've tried setting the PrimaryYAxis.Range.Min = 0.1 but that doesn't do anything.The code is listed below, which first sets up the chart and then loads the data. Thanks in advance. Private Sub SetupChart()
        _BubblePlot.ImprovePerformance = True

        _BubblePlot.CalcRegions = False
        ForeColor = Color.DarkBlue
        BackColor = Color.AliceBlue
        Font = New Font("Trebuchet MS", 8)
        _BubblePlot.BackInterior = New BrushInfo(GradientStyle.None, Color.AliceBlue, Color.AliceBlue)
        _BubblePlot.ChartInterior = New BrushInfo(GradientStyle.ForwardDiagonal, Color.LightSteelBlue, Color.AliceBlue)
        _BubblePlot.ChartArea.BackInterior = New BrushInfo(GradientStyle.None, Color.AliceBlue, Color.AliceBlue)

        _BubblePlot.PrimaryXAxis.Title = "Oerflow Duration (Hours)"
        _BubblePlot.PrimaryXAxis.Format = "F0"
        _BubblePlot.PrimaryXAxis.ValueType = ChartValueType.Double

        _BubblePlot.PrimaryYAxis.Title = "Storm Return Period (Years)"
        _BubblePlot.PrimaryYAxis.Format = "0.#"
        _BubblePlot.PrimaryYAxis.ValueType = ChartValueType.Logarithmic
        _BubblePlot.PrimaryYAxis.Origin = 0.1

        _BubblePlot.PrimaryXAxis.TitleFont = New System.Drawing.Font("Verdana", 9.0F, FontStyle.Bold)
        _BubblePlot.PrimaryXAxis.TitleColor = Color.SteelBlue

        _BubblePlot.PrimaryYAxis.TitleFont = New System.Drawing.Font("Verdana", 9.0F, FontStyle.Bold)
        _BubblePlot.PrimaryYAxis.TitleColor = Color.SteelBlue

        _BubblePlot.PrimaryXAxis.LabelAlignment = StringAlignment.Center

        _BubblePlot.Titles.Clear()
        Dim _Title As Syncfusion.Windows.Forms.Chart.ChartTitle

        '>Main Title
        _Title = New Syncfusion.Windows.Forms.Chart.ChartTitle
        _Title.Text = "Bubble Size Reflects Relative Volume of Overflow"
        _Title.Font = New System.Drawing.Font("Verdana", 12.0!, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        _BubblePlot.Titles.Add(_Title)

        _Title = New Syncfusion.Windows.Forms.Chart.ChartTitle
        _Title.Text = Globals.Project.CSOBasin

        _Title.Font = New System.Drawing.Font("Verdana", 10.0!, System.Drawing.FontStyle.Italic, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        _Title.Position = ChartDock.Bottom
        _Title.Alignment = ChartAlignment.Far
        _Title.Margin = 0
        _BubblePlot.Titles.Add(_Title)
    End Sub

    Private Sub LoadChartData()
        Dim RarestDuration(Globals.Project.NoCSOs - 1) As Single, RarestStormTr(Globals.Project.NoCSOs - 1) As Single
        Dim CSODate(Globals.Project.NoCSOs - 1) As Date, CSODuration(Globals.Project.NoCSOs - 1) As Single, CSOVolume(Globals.Project.NoCSOs - 1) As Single

        _BubblePlot.Series.Clear()

        Globals.Project.RarestCSOResultsGet(RarestDuration, RarestStormTr)
        Globals.Project.CSODataGet(CSODate, CSODuration, CSOVolume)

        _series = New ChartSeries("Bubble", ChartSeriesType.Bubble)

        _series.Style.Symbol.Color = Color.Blue
        _BubblePlot.PrimaryYAxis.Range.Min = 0.1

        For I As Integer = Globals.Project.NoCSOs - 1 To 0 Step -1
            _series.Points.Add(CSODuration(I), RarestStormTr(I), CSOVolume(I))
        Next

        _BubblePlot.Series.Add(_series)
        _BubblePlot.Refresh()

    ------End Sub

Bruce Barker · Answer

I solved it. The min and max values for the axis are specified in log space. For a min value of 0.01 and a max of 1000 you specify: PrimaryYAxis.Range.Min=Math.log10(0.01)PrimaryYAxis.Range.Max=Math.log10(1000.0)

Vijayabharathi K · Answer

Hi
Bruce,



Thanks
for using Syncfusion products.



Please let us know if you require
any further assistance.



Regards,

Vijayabharathi