Bug 210635 Incorrect preview of chart after reverse categories.
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/computation/withaxes/PlotWith2DAxes.java
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( );
						if ( Math.min( asDouble( oMin ).doubleValue( ), dV1 ) == dV1 )
						{
							oMin = oV1;
						}
					}
				}
				if ( oV2 != null ) 
				{
					if ( oMax == null )
					{
						oMax = oV2;
					}
					else
					{
						final double dV2 = asDouble( oV2 ).doubleValue( );
						if ( Math.max( asDouble( oMax ).doubleValue( ), dV2 ) == dV2 )