public double[] extractDataDouble (int start,int length)	{
		try	{
			int count=0,a=circBufferCounter+start;
			double outData[]=new double[length];
			if (a>=MAXCIRC) a=a-MAXCIRC;
			for (count=0;count<length;count++)	{
				outData[count]=circDataBuffer[a];
				a++;
				if (a==MAXCIRC) a=0;
			}
			return outData;
		}
		catch (Exception e)	{
			JOptionPane.showMessageDialog(null,"Error in extractDataDouble() "+e.toString(),"Rivet", JOptionPane.ERROR_MESSAGE);
			return null;
		}
	}