def m2px(m, points, scan_size):
    """
    Converts length in metres to a length in pixels

    Parameters
    ----------
    m : int or float
        length in metres to be converted
    points : int
        number of lines or points per row
    scan_size : int or float
        total length of scan

    Returns
    -------
    px : float
        converted length in pixels
    """
    px = m * points / scan_size
    return px