ENH: Read and store "START" and "END" events from EDF file

[scott-huberty]

Closes #17

These events indicate when the Eye-tracker started and stopped recording, respectively. There can be multiple of these events, meaning that the eye-tracker started recording, paused, and then started recording again (e.g. during a calibration sequence or between trials). Sometimes there is a large time span between an END event and a subsequent START event, meaning there is a pause/gap in the recording that the user might want to know about.

The pyeparse authors appeared to know about "START" and "END events in EDF files, but they just used python's pass to skip these events when reading the EDF files.

I adjusted our event handlers to give both start and end events an entry in EDF["discrete"].

For example

import eyelinkio
fname = eyelinkio.utils._get_test_fnames()[2]
edf = eyelinkio.read_edf(fname)

edf["discrete"]["starts"]

array([(  0.   ,), ( 11.032,), ( 17.674,), ( 39.3  ,), ( 60.926,),
       ( 67.562,), ( 78.766,), ( 85.402,), ( 92.022,), ( 98.844,),
       (120.47 ,), (142.086,), (156.532,), (175.848,), (197.466,)],
      dtype=[('stime', '<f8')])

edf["discrete"]["ends"]

array([( 11.0300007 ,), ( 17.67200078,), ( 39.29800084,), ( 60.92400067,),
       ( 67.56000069,), ( 78.76400077,), ( 85.40000075,), ( 92.02000076,),
       ( 98.84200089,), (120.46800086,), (142.0840008 ,), (156.53000088,),
       (175.84600069,), (197.4640009 ,), (199.644     ,)],
      dtype=[('stime', '<f8')])

and for reference, attached is an ASCII version of the same file used in the example above, where you can see the START and END events.

test_raw_binocular.txt

[scott-huberty]

@teonbrooks would you be available to provide a review?

[teonbrooks]

sorry I didn't get around to this in time

[scott-huberty]

sorry I didn't get around to this in time

No worries!