Bug 212370 [Regression] Negative value can not be shown both in chart builder and when preview [13]
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/computation/withaxes/PlotWith2DAxes.java
{
				if ( sea[i].canBeStacked( ) )
				{
					bAnyStacked = true;
					continue;
				}
				else
				{
					throw new IllegalArgumentException( MessageFormat.format( Messages.getResourceBundle( rtc.getULocale( ) )
							.getString( "exception.unstackable.is.stacked" ), 
							new Object[]{
								sea[i]
							} ) );
				}
			}
			iDSP = ps.getDataSetProcessor( sea[i].getClass( ) );
			ds = sea[i].getDataSet( );
			oV1 = iDSP.getMinimum( ds );
			oV2 = iDSP.getMaximum( ds );
			if ( ( iType & NUMERICAL ) == NUMERICAL )
			{
				if ( oV1 != null ) 
				{
					if ( oMin == null )
					{
						oMin = oV1;
					}
					else
					{
						final double dV1 = asDouble( oV1 ).doubleValue( );