Sub NPlotSurface(ByVal Data As ArrayList, ByVal FreqPoints As Integer, ByVal AnglePoints As Integer, ByVal Flat As Boolean, ByVal TitleText As String, ByVal NChart1 As NChartControl)

        If Not IsNothing(Data) AndAlso Data.Count > 0 Then

            NChart1.Clear()

            ' set the initial chart title
            Dim title As NLabel = NChart1.Labels.AddHeader(TitleText)
            title.TextStyle.FontStyle = New NFontStyle("Century Gothic", 15, FontStyle.Regular)

            ' setup chart
            Dim chart As NChart = NChart1.Charts(0)

            If Not Flat Then
                NChart1.Controller.Tools.Add(New NSelectorTool())
                NChart1.Controller.Tools.Add(New NTrackballTool())
            End If

            NChart1.BackgroundStyle.FrameStyle.Visible = False
            chart.Wall(ChartWallType.Back).BorderStyle.Width = New NLength(0)

            chart.Enable3D = True

            If Flat Then
                chart.Height = 0.1F
                chart.Width = 75.0F
                chart.Depth = 75.0F
                chart.Projection.SetPredefinedProjection(PredefinedProjection.OrthogonalTop)
                '           chart.LightModel.EnableLighting = False
            Else
                chart.Height = 45.0F
                chart.Width = 60.0F
                chart.Depth = 60.0F
                chart.Projection.SetPredefinedProjection(PredefinedProjection.PerspectiveTilted)
                'chart.LightModel.SetPredefinedLightModel(PredefinedLightModel.ShinyTopLeft)
                'chart.LightModel.EnableLighting = True
            End If

            ' setup axes
            Dim linearScale As NLinearScaleConfigurator = New NLinearScaleConfigurator()
            linearScale.MajorGridStyle.SetShowAtWall(ChartWallType.Floor, True)
            linearScale.MajorGridStyle.SetShowAtWall(ChartWallType.Back, True)

            linearScale.RoundToTickMax = False
            linearScale.RoundToTickMin = False
            chart.Axis(StandardAxis.PrimaryX).ScaleConfigurator = linearScale
            linearScale.Title.Text = "Angle Degrees"

            Dim scaleConfiguratorY As NStandardScaleConfigurator = CType(chart.Axis(StandardAxis.PrimaryY).ScaleConfigurator, NStandardScaleConfigurator)
            scaleConfiguratorY.Title.Text = "Gain (" & dBunits & ")"

            Dim scaleConfiguratorZ As NStandardScaleConfigurator = CType(chart.Axis(StandardAxis.SecondaryY).ScaleConfigurator, NStandardScaleConfigurator)
            scaleConfiguratorZ.Title.Text = "Frequency (MHz)"

            linearScale = New NLinearScaleConfigurator()
            linearScale.MajorGridStyle.SetShowAtWall(ChartWallType.Floor, True)
            linearScale.MajorGridStyle.SetShowAtWall(ChartWallType.Left, True)

            linearScale.RoundToTickMax = False
            linearScale.RoundToTickMin = False
            chart.Axis(StandardAxis.Depth).ScaleConfigurator = linearScale

            ' setup surface series
            Dim surface As NMeshSurfaceSeries = CType(chart.Series.Add(SeriesType.MeshSurface), NMeshSurfaceSeries)
            surface.Name = "Surface"
            surface.Legend.Mode = SeriesLegendMode.SeriesLogic

            surface.FrameMode = SurfaceFrameMode.Contour
            surface.FillMode = SurfaceFillMode.Zone

            'surface.FillStyle = New NColorFillStyle(Color.YellowGreen)
            'surface.ShadingMode = ShadingMode.Flat

            If Flat Then
                surface.DrawFlat = True
            Else
                surface.DrawFlat = False
            End If

            surface.PositionValue = 0.5

            surface.Data.SetGridSize(AnglePoints, FreqPoints)

            Dim AngleCounter = 0
            Dim FreqCounter = 0

            Dim MaxAmp = -900.0
            Dim MinAmp = 900.0

            For Each dp In Data

                MaxAmp = Max(MaxAmp, dp.Ampl)
                MinAmp = Min(MinAmp, dp.Ampl)

                surface.Data.SetValue(AngleCounter, FreqCounter, dp.ampl, dp.angle, dp.freq / 1000000)

                FreqCounter += 1

                If FreqCounter = FreqPoints Then
                    FreqCounter = 0
                    AngleCounter += 1
                End If

            Next

            ' setup a custom palette

            surface.SyncPaletteWithAxisScale = False
            surface.SmoothPalette = False
            surface.AutomaticPalette = False
            surface.Palette.Clear()

            ' automatic legend
            'surface.Legend.Format = "<zone_end> to <zone_begin>"
            'surface.ValueFormatter.FormatSpecifier = "0.0"

            ' legend

            Dim Colors = {Color.Red, Color.Red, Color.Orange, Color.Yellow, Color.LightGreen, Color.LimeGreen, Color.CornflowerBlue, Color.MediumSlateBlue, Color.Purple}
            Dim PaletteSteps As Double()    ' array of doubles
            Dim PaletteCount As Integer = 8
            Dim LegendItems As NLegendItemCellData()
            Dim i0, i1, i2, i3, i4, i5, i6, i7, i8, i9, i10, i11, i12, i13, i14, i15 As New NLegendItemCellData
            LegendItems = {i0, i1, i2, i3, i4, i5, i6, i7, i8, i9, i10, i11, i12, i13, i14, i15}

            Dim legendsCollection As NLegendCollection = NChart1.Legends
            Dim legend As NLegend = CType(legendsCollection(0), NLegend)
            legend.Margins = New NMarginsL(10, 10, 10, 10)
            legend.Dock = DockStyle.Right
            legend.Mode = LegendMode.Manual
            legend.ShadowStyle.Type = ShadowType.Solid

            'legend.OuterLeftBorderStyle.Width = New NLength(0)
            'legend.OuterTopBorderStyle.Width = New NLength(0)
            'legend.OuterRightBorderStyle.Width = New NLength(0)
            'legend.OuterBottomBorderStyle.Width = New NLength(0)
            legend.HorizontalBorderStyle.Width = New NLength(0)
            legend.VerticalBorderStyle.Width = New NLength(0)

            legend.Data.ExpandMode = LegendExpandMode.ColsFixed
            legend.Data.ColCount = 2

            If MaxAmp - MinAmp > 20 Then
                PaletteSteps = {0, 1, 2, 3, 6, 9, 12, 15, MaxAmp - MinAmp}
            ElseIf MaxAmp - MinAmp > 10 Then
                PaletteSteps = {0, 1, 2, 3, 4, 5, 6, 7, MaxAmp - MinAmp}
            ElseIf MaxAmp - MinAmp > 4 Then
                PaletteSteps = {0, 0.5, 1, 1.5, 2, 2.5, 3, 4, MaxAmp - MinAmp}
            Else
                PaletteSteps = {0, 0.1, 0.2, 0.4, 0.6, 0.8, 1, 2, MaxAmp - MinAmp}
            End If

            For i = 0 To PaletteCount
                surface.Palette.Add(MaxAmp - PaletteSteps(i), Colors(i))

                If i <> 0 Then

                    LegendItems((i - 1) * 2) = New NLegendItemCellData

                    LegendItems((i - 1) * 2).MarkShape = LegendMarkShape.None
                    LegendItems((i - 1) * 2).MarkLineStyle.Width = New NLength(3, NGraphicsUnit.Pixel)
                    LegendItems((i - 1) * 2).MarkLineStyle.Color = Colors(i)
                    legend.Data.Items.Add(LegendItems((i - 1) * 2))

                    LegendItems((i - 1) * 2 + 1).Text = Round(MaxAmp - PaletteSteps(i - 1), 2) & " to " & Round(MaxAmp - PaletteSteps(i), 2)
                    LegendItems((i - 1) * 2 + 1).MarkShape = LegendMarkShape.None
                    LegendItems((i - 1) * 2 + 1).MarkLineStyle.Width = New NLength(0, NGraphicsUnit.Pixel)
                    legend.Data.Items.Add(LegendItems((i - 1) * 2 + 1))
                End If
            Next

            ' configure horizontal interlacing
            Dim m_RowInterlaceStyle As New NLegendInterlaceStyle

            m_RowInterlaceStyle.Begin = 1
            m_RowInterlaceStyle.Length = 1
            m_RowInterlaceStyle.Interval = 1
            m_RowInterlaceStyle.FillStyle = New NColorFillStyle(Color.FromArgb(125, Color.LightGray))

            legend.InterlaceStyles.Add(m_RowInterlaceStyle)

            NChart1.Refresh()
        End If
    End Sub