Bug 130688 ULocal unsupported(Data)
core/org.eclipse.birt.core/src/org/eclipse/birt/core/data/DataTypeUtil.java
* 		true 	-> 1
	 * 		others 	-> 0 
	 * Date -> Double
	 * 		Date.getTime();
	 * String -> Double
	 * 		Double.valueOf(String);
	 * @param source
	 * @return
	 * @throws BirtException
	 */
	public static Double toDouble( Object source ) throws BirtException
	{
		if ( source == null )
			return null;
		
		if ( source instanceof Integer )
		{
			double doubleValue = ( (Integer) source ).doubleValue( );
			return new Double( doubleValue );
		}
		else if ( source instanceof BigDecimal )
		{
			double doubleValue = ( (BigDecimal) source ).doubleValue( );
			return new Double( doubleValue );
		}
		else if ( source instanceof Boolean )
		{
			if ( true == ( (Boolean) source ).booleanValue( ) )
				return new Double( 1d );
			return new Double( 0d );