@classmethod
def simple(cls, df, missing, maxdist, mindur):
    """Detects fixations, defined as consecutive samples with an inter-sample distance of less than a set amount of 
		pixels (disregarding missing data).
   
		Parameters
		----------
		df : :class:`pandas.DataFrame`
			Pandas dataframe of x,y and timestamp positions
		missing : :obj:`str`
			Value to be used for missing data (default = 0.0)
		maxdist : :obj:`str`
			Maximal inter-sample distance in pixels (default = 25)
		mindur : :obj:`str`
			Minimal duration of a fixation in milliseconds; detected fixation cadidates will be 
			disregarded if they are below this duration (default = 100).

		Returns
		-------
		Sfix : :class:`numpy.ndarray` shape (N)
			list of lists, each containing [starttime]
		Efix : :class:`numpy.ndarray` shape (N)
			list of lists, each containing [starttime, endtime, duration, endx, endy]

		Notes
		-----
		From https://github.com/esdalmaijer/PyGazeAnalyser/blob/master/pygazeanalyser/detectors.py

		"""
    x = df['x']
    y = df['y']
    time = df['timestamp']
    Sfix = []
    Efix = []
    si = 0
    fixstart = False
    for i in range(1, len(x)):
        dist = ((x[si] - x[i]) ** 2 + (y[si] - y[i]) ** 2) ** 0.5
        if dist <= maxdist and not fixstart:
            si = 0 + i
            fixstart = True
            Sfix.append([time[i]])
        elif dist > maxdist and fixstart:
            fixstart = False
            if time[i - 1] - Sfix[-1][0] >= mindur:
                Efix.append([Sfix[-1][0], time[i - 1], time[i - 1] - Sfix[-
                    1][0], x[si], y[si]])
            else:
                Sfix.pop(-1)
            si = 0 + i
        elif not fixstart:
            si += 1
    return Sfix, Efix
