public class BubbleSeries : Series 

var workbook = Workbook.Create( ChartSample.ChartSampleOutputDirectory + @"AddCharts.xlsx" );

// Gets the first Worksheet. A Workbook always contains at least 1 Worksheet.
var worksheet = workbook.Worksheets[ 0 ];

// Adds Values for Category.
worksheet.Cells[ "B4" ].Value = 2020;
worksheet.Cells[ "B5" ].Value = 2021;
worksheet.Cells[ "B6" ].Value = 2022;
worksheet.Cells[ "B7" ].Value = 2023;
worksheet.Cells[ "B8" ].Value = 2024;

// Adds Values for Series.
worksheet.Cells[ "C4" ].Value = 20d;
worksheet.Cells[ "C5" ].Value = 28d;
worksheet.Cells[ "C6" ].Value = 33d;
worksheet.Cells[ "C7" ].Value = 12d;
worksheet.Cells[ "C8" ].Value = 45d;

// Adds a BubbleChart with the generic Add method and set its SubType. The size of the Chart will be from Cell E4 to L18.
var bubbleChart = worksheet.Charts.Add<BubbleChart>( "E4", "L18" );
bubbleChart.SubType = BubbleChartSubType.Bubble3D;

// Sets the Chart's Title.
bubbleChart.Title.Text = "Profits";
bubbleChart.Title.TextOptions.Font.Bold = true;

// Sets the Legend.
bubbleChart.Legend.Position = LegendPositionType.Right;

// Sets the Category data(x values) for the BubbleChart : Cells B4 to B8.
bubbleChart.CategoryData = CategoryData.FromCells( worksheet, "B4", "B8" );

// Scales the Chart's bubble to 50%.
bubbleChart.BubbleScale = 50;

// Adds BubbleSeries to the BubbleChart (y values) by specifying fixed values and a range of Cells’ Adresses.
var bubbleSeries1 = bubbleChart.SeriesCollection.AddFromValues<BubbleSeries>( 5d, 10d, 15d, 20d, 40d );
bubbleSeries1.Name = "IBM";
var bubbleSeries2 = bubbleChart.SeriesCollection.AddFromCells<BubbleSeries>( "C4", "C8" );
bubbleSeries2.Name = "Apple";

// Sets the sizes of the bubbles based on their value.
var bubbleSeriesSize = new List<double>();
bubbleSeries1.Values.Cast<double>().ToList().ForEach( value => bubbleSeriesSize.Add( value / 5 ) );
bubbleSeries1.BubbleSizes = bubbleSeriesSize.ToArray();
bubbleSeriesSize.Clear();
bubbleSeries2.Values.Cast<double>().ToList().ForEach( value => bubbleSeriesSize.Add( value / 5 ) );        
bubbleSeries2.BubbleSizes = bubbleSeriesSize.ToArray();

// Shows the DataPoint Labels for the BubbleSeries and positions them.
bubbleSeries1.DataPointLabels.ShowValue = true;
bubbleSeries1.DataPointLabels.Position = PointDataPointLabelsPositionType.Right;
bubbleSeries1.DataPointLabels.ShowBubbleSize = true;
bubbleSeries2.DataPointLabels.ShowValue = true;
bubbleSeries2.DataPointLabels.Position = PointDataPointLabelsPositionType.Right;
bubbleSeries2.DataPointLabels.ShowBubbleSize = true;

// Saves Workbook to disk.
workbook.Save();