def conv_lin(a, b=1.0, c=0.0, inverse=False):
    """Simple linear transform
        will I think store parameters against each sensor then they are handy
        >>> conv_lin(4,2,3)
        11
        >>> conv_lin(11,2,3.0,True)
        4.0
        >>>"""
    if inverse is False:
        return a * b + c
    else:
        return (a - c) / b