def _polynomial_conversion(data, conversion):
    """ apply polynomial conversion to data

    Parameters
    ----------------
    data : numpy 1D array
        raw data to be converted to physical value
    conversion : mdfinfo3.info3 conversion block ('CCBlock') dict

    Returns
    -----------
    converted data to physical value
    """
    return (conversion['P2'] - conversion['P4'] * (data - conversion['P5'] -
        conversion['P6'])) / (conversion['P3'] * (data - conversion['P5'] -
        conversion['P6']) - conversion['P1'])
