protected static Ptg calcMMult( Ptg[] operands )
	{
		if( operands.length != 2 )
		{
			return PtgCalculator.getNAError();
		}
		try
		{
			// error trap params:  must be numeric arrays with no empty spaces	
			double[][] a1 = PtgCalculator.getArray( operands[0] );
			double[][] a2 = PtgCalculator.getArray( operands[1] );
			if( a1[0].length != a2.length )
			{
				PtgCalculator.getValueError();
			}
			double sum = 0.0;
			for( int i = 0; i < a1[0].length; i++ )
			{
				sum += a1[0][i] * a2[i][0];
			}
			return new PtgNumber( sum );
		}
		catch( Exception e )
		{
//		log.error("MMULT: error in operands " + e.toString());
		}
		return PtgCalculator.getValueError();
	}