void average_columns(int nNumColsOfOneGroup = 16)
{
	// get source data worksheet containing one X-column and 512 Y-columns
	Worksheet wks = Project.ActiveLayer();
	if(!wks || 513 != wks.GetNumCols())
	{
		out_str("No active worksheet or no specified worksheet including one X column and 512 Y columns!");
		return;
	}
	
	//prepare output worksheet
	Worksheet wksOut;
	wksOut.Create("origin");
	
	// Copy X data from source worksheet to reuslt worksheet
	Dataset dsX(wks, 0);
	Dataset dsXNew(wksOut, 0);
	dsXNew = dsX;
		
	// average Y columns for each 16 columns and put result to new worksheet
	int nBeginCol = 1; 
	int nEndCol = nBeginCol + nNumColsOfOneGroup - 1;
	int nResultCol = 1; //the first column is X, so the first Y column beginning from 1
	for(int nNumGroups = 0; ;nNumGroups++)
	{
		// get data and do average
		Column colBegin(wks, nBeginCol);
		if(!colBegin)
			break;
		
		vector& vData1 = colBegin.GetDataObject();
		for(int nCol = nBeginCol+1; nCol <= nEndCol; nCol++)
		{
			Column col(wks, nCol);
			if(!col)
				break;
			
			vector& vData2 = col.GetDataObject();
			vData1 = vData1 + vData2;
		}		
		vData1 = vData1 / nNumColsOfOneGroup;
		
		// put reuslt into wksOut sheet
		Column colResult(wksOut, nResultCol);
		if(!colResult)
			colResult.Attach(wksOut, wksOut.AddCol());
		Dataset dsResult(colResult);
		dsResult = vData1;
		nResultCol++;
		
		// continue to average next group
		nBeginCol += nNumColsOfOneGroup;
		nEndCol += nNumColsOfOneGroup;
	}	
}