Data Files
©
2016-2017 SR Research Ltd.
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START lines mark the beginning of a block of recorded samples, events, or both.
The start time is followed by a list of keywords which specify the eye recorded
from, and the types of data lines in the block. The eye recorded from is specified
by "LEFT" for left-eye, "RIGHT" for right-eye, and both "LEFT" and "RIGHT" for
binocular. The types of data lines included are specified by "SAMPLES" for
samples only, "EVENTS" for events only, and both "SAMPLES" and "EVENTS"
for both.
END lines mark the end of a block of data. The <types> are specified, as it is
possible to turn recording of samples and events on and off independently.
However, this is not suggested, and for most applications the <types> in the
END line can be ignored. The two values following the "RES" keyword are the
average resolution for the block: if samples are present, it is computed from
samples; otherwise it summarizes any resolution data in the events. Note that
resolution data may be missing: this is represented by a dot (".") instead of a
number for the resolution.
4.9.3.4 Fixations
•
SFIX <eye> <stime>
•
EFIX <eye> <stime> <etime> <dur> <axp> <ayp> <aps>
•
EFIX <eye> <stime> <etime> <dur> <axp> <ayp> <aps> <xr> <yr>
The start of fixations are reported with a SFIX line, which can be eliminated
with the EDF2ASC "-nse" option. The <eye> is "L" or "R", indicating the eye's
data that produced the event.
The end of and summary data on the fixation is reported with the EFIX line.
This reports the time of the first and last sample in the fixation, and computes
the duration of the fixation in milliseconds. The average X and Y eye position
(the type of position data is determined when the event was generated) and the
average pupil size (area or diameter) are reported. Optionally, the eye-position
angular resolution (in units per visual degree) is given as well.
All samples that are within the fixation will be listed between the SFIX and EFIX
event for each eye, simplifying data analysis.
4.9.3.5 Saccades
•
SSACC <eye> <stime>
•
ESACC <eye> <stime> <etime> <dur> <sxp> <syp> <exp> <eyp> <ampl> <pv>
•
ESACC <eye> <stime> <etime> <dur> <sxp> <syp> <exp> <eyp> <ampl> <pv>
<xr> <yr>
