Bug 214197 [Regression] Auto scale does not work correctly [13]
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/computation/withaxes/AutoScale.java
* 
	 * @return step number
	 */
	public final Integer getStepNumber( )
	{
		return oStepNumber;
	}
	public final void setStepNumber( Integer o )
	{
		this.oStepNumber = o;
	}
	/**
	 * 
	 * @return
	 */
	final Object[] getMinMax( ) throws ChartException
	{
		Object oValue = null;
		try
		{
			if ( ( iType & NUMERICAL ) == NUMERICAL )
			{
				double dValue, dMinValue = Double.MAX_VALUE, dMaxValue = -Double.MAX_VALUE;
				dsiData.reset( );
				while ( dsiData.hasNext( ) )
				{
					oValue = dsiData.next( );
					if ( oValue == null ) 
					{
						continue;