Bug 193263 Inconsistent result of average function between Chart and Table[0001]
Description: Set average function on Chart and Table, get the different result. Chart engine takes the null value as 0, but in DTE null will be discarded. I have checked the behavior of excel, the null value is discarded in it. Build version:2.2.0v20070619-0630 Steps to reproduce: 1. Get the attached report design file and preview.
chart/org.eclipse.birt.chart.ui.extension/src/org/eclipse/birt/chart/ui/swt/series/DifferenceSeriesAttributeComposite.java
}
		
		btnPalette = new Button( cmpButton, SWT.CHECK );
		{
			btnPalette.setLayoutData( new GridData( ) );
			btnPalette.setText( Messages.getString( "DifferenceSeriesAttributeComposite.Lbl.LinePalette" ) ); 
			btnPalette.setSelection( ( (LineSeries) series ).isPaletteLineColor( ) );
			btnPalette.addSelectionListener( this );
		}
		btnCurve = new Button( cmpButton, SWT.CHECK );
		{
			btnCurve.setLayoutData( new GridData( ) );
			btnCurve.setText( Messages.getString( "DifferenceSeriesAttributeComposite.Lbl.ShowLinesAsCurves" ) ); 
			btnCurve.setSelection( ( (DifferenceSeries) series ).isCurve( ) );
			btnCurve.addSelectionListener( this );
		}
		enableLineSettings( ( (DifferenceSeries) series ).getLineAttributes( )
				.isVisible( )
				|| ( (DifferenceSeries) series ).getNegativeLineAttributes( )
						.isVisible( ) );
	}
	public Point getPreferredSize( )
	{
		return new Point( 400, 200 );
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.swt.events.SelectionListener#widgetSelected(org.eclipse.swt.events.SelectionEvent)
	 */