There is sample code, excel file attached
TempFileCollection tempFileCollection = new TempFileCollection();
Workbook workbook = new Workbook();
//Set default font
Style style = workbook.DefaultStyle;
style.Font.Name = "Tahoma";
workbook.DefaultStyle = style;
Worksheet sheet = workbook.Worksheets[0];
//Set the name of worksheet
sheet.Name = "Data";
sheet.IsGridlinesVisible = false;
Cells cells = workbook.Worksheets[0].Cells;
//Put a value into a cell
cells["A1"].PutValue("Brand Name");
cells["B1"].PutValue("Vitamin A");
cells["C1"].PutValue("Vitamin B1");
cells["D1"].PutValue("Vitamin B2");
cells["E1"].PutValue("Vitamin C");
cells["F1"].PutValue("Vitamin D");
cells["G1"].PutValue("Vitamin E");
cells["A2"].PutValue("Brand A");
cells["B2"].PutValue(100);
cells["C2"].PutValue(100);
cells["D2"].PutValue(100);
cells["E2"].PutValue(80);
cells["F2"].PutValue(100);
cells["G2"].PutValue(70);
cells["A3"].PutValue("Brand B");
cells["B3"].PutValue(80);
cells["C3"].PutValue(75);
cells["D3"].PutValue(80);
cells["E3"].PutValue(100);
cells["F3"].PutValue(50);
cells["G3"].PutValue(15);
cells["A4"].PutValue("Brand C");
cells["B4"].PutValue(40);
cells["C4"].PutValue(25);
cells["D4"].PutValue(40);
cells["E4"].PutValue(55);
cells["F4"].PutValue(30);
cells["G4"].PutValue(10);
int sheetIndex = workbook.Worksheets.Add();
Worksheet sheet2 = workbook.Worksheets[sheetIndex];
//Set the name of worksheet
sheet2.Name = "Chart";
//Create chart
int chartIndex = sheet2.Charts.Add(ChartType.RadarFilled, 1, 1, 25, 10);
Chart chart = sheet2.Charts[chartIndex];
//Set properties of chart
chart.PlotArea.Border.IsVisible = false;
//Set properties of chart title
chart.Title.Text = "Nutritional Analysis";
chart.Title.TextFont.Color = Color.Black;
chart.Title.TextFont.IsBold = true;
chart.Title.TextFont.Size = 12;
//Set properties of nseries
chart.NSeries.Add("Data!B2:G2", false);
chart.NSeries.CategoryData = "Data!B1:G1";
chart.PlotArea.Area.ForegroundColor = Color.Green;
chart.NSeries[0].Area.ForegroundColor = Color.Red;
workbook.Save("d:\\FilledRadarChart.xls");
Bitmap image = chart.ToImage();
string imageName = tempFileCollection.AddExtension("PDFChart.jpg", true);
image.Save(imageName, ImageFormat.Jpeg);