var spread = new GC.Spread.Sheets.Workbook(document.getElementById("ss"),{sheetCount:3});
var sourceSheet = spread.getSheet(0);
var sheet = spread.getSheet(1);
var sourceData = [["Date","Buyer","Type","Amount"],
["01-Jan","Mom","Fuel",74],
["15-Jan","Mom","Food",235],
["17-Jan","Dad","Sports",20],
["21-Jan","Kelly","Books",125]];
sourceSheet.setArray(0, 0, sourceData );
sourceSheet.tables.add('sourceData', 0, 0, 5, 4);
var layout = GC.Spread.Pivot.PivotTableLayoutType.compact;
var theme = GC.Spread.Pivot.PivotTableThemes.medium2;
var options = {showRowHeader: true, showColumnHeader: true};
var pivotTable = sheet.pivotTables.add("pivotTable_1", 'sourceData', 1, 1, layout, theme, options);
pivotTable.theme("light3");