Bug 118738 can't preview meter chart with grouping
Try to preview the following report with a meter chart group on the Y series, it fails. It used to work before, this is a regression. An exception is thrown org.eclipse.birt.chart.exception.ChartException: Can not plot meter series with null or non-numeric datapoint. at org.eclipse.birt.chart.render.DialRenderer.<init>(DialRenderer.java:132) at org.eclipse.birt.chart.render.Dial.compute(Dial.java:98) at org.eclipse.birt.chart.factory.Generator.build(Generator.java:759)
chart/org.eclipse.birt.chart.device.extension/src/org/eclipse/birt/chart/device/image/JavaxImageIOWriter.java
protected Image _img = null;
	protected Object _oOutputIdentifier = null;
	private Bounds _bo = null;
	private transient boolean _bImageExternallySpecified = false;
	private static ILogger logger = Logger.getLogger( "org.eclipse.birt.chart.device.extension/image" ); 
	/**
	 * Returns the output format string for this writer.
	 * 
	 * @return
	 */
	protected abstract String getFormat( );
	/**
	 * Returns the output image type for this writer.
	 * 
	 * @see java.awt.image.BufferedImage#TYPE_INT_RGB
	 * @see java.awt.image.BufferedImage#TYPE_INT_ARGB
	 * @see java.awt.image.BufferedImage#TYPE_INT_ARGB_PRE
	 * @see java.awt.image.BufferedImage#TYPE_INT_BGR
	 * @see java.awt.image.BufferedImage#TYPE_3BYTE_BGR
	 * @see java.awt.image.BufferedImage#TYPE_4BYTE_ABGR
	 * @see java.awt.image.BufferedImage#TYPE_4BYTE_ABGR_PRE
	 * @see java.awt.image.BufferedImage#TYPE_BYTE_GRAY
	 * @see java.awt.image.BufferedImage#TYPE_USHORT_GRAY
	 * @see java.awt.image.BufferedImage#TYPE_BYTE_BINARY
	 * @see java.awt.image.BufferedImage#TYPE_BYTE_INDEXED
	 * @see java.awt.image.BufferedImage#TYPE_USHORT_565_RGB
	 * @see java.awt.image.BufferedImage#TYPE_USHORT_555_RGB
	 * 
	 * @return
	 */