Sebastiaan Mathôt and contributors
Copyright 2016-2023
http://www.cogsci.nl/smathot
The python-eyelinkparser
module provides a framework to parse EyeLink data files in .asc
format, that is, the format that you get after converting an .edf
file with edf2asc
. This module is mostly for personal use, and is not very well documented.
pip install eyelinkparser
The parser assumes monocular recording.
By default, the parser assumes that particular messages are sent to the logfile. If you use different messages, you need to override functions in _eyelinkparser.EyeLinkParser
. This is not explained here, but you can look in the source code to see how it works.
Trial start:
start_trial [trialid]
Trial end:
end_trial
stop_trial
Variables:
var [name] [value]
Start of a period of continuous data:
start_phase [name]
phase [name]
End of a period of continuous data:
end_phase [name]
stop_phase [name]
The main parser class. This is generally not created directly, but
through the eyelinkparser.parse()
function, which takes the same keywords
as the EyeLinkParser
constructor (i.e. the keywords below).
folder: str, optional
The folder that contains .edf or .asc data files, or files compressed as .tar.xz archives.
ext: str or tuple, optional
Allowed file extensions, or a tuple of extensions, for data files.
downsample: int or None, optional
Indicates whether traces (if any) should be downsampled. For example, a value of 10 means that the signal becomes 10 times shorter. Downsample creates a simple traceprocessor, and can therefore not be used in combination with the traceprocessor argument.
maxtracelen: int or None, optional
A maximum length for traces. Longer traces are truncated and a
UserWarning
is emitted. This length refers to the trace after
downsampling/ processing.
traceprocessor: callable or None, optional
A function that is applied to each trace before the trace is written to the SeriesColumn. This can be used to apply a series of operations that are best done on the raw signal, such as first correcting blinks and then downsampling the signal.
The function must accept two arguments: first a label for the trace, which is 'pupil', 'xcoor', 'ycoor', or 'time'. This allows the function to distinguish the different kinds of singals; second, the trace itself.
See eyelinkparser.defaulttraceprocessor
for a convenience function
that applies blink correction and downsampling.
trialphase: str or None, optional
Indicates the name of a phase that should be automatically started when
the trial starts, or None
when no trial should be automatically
started. This is mostly convenient for processing trials that consist
of a single long epoch, or when no start_phase
messages were written
to the log file.
phasefilter: callable or None, optional
A function that receives a phase name as argument, and returns a bool indicating whether that phase should be retained.
phasemap: dict, optional
A dict in which keys are phase names that are renamed to the associated values. This is mostly useful to merge subsequent traces, in which case the key is the first trace and the value is the second trace.
edf2asc_binary: str, optional
The name of the edf2asc executable, which if available can be used to automatically convert .edf files to .asc. If not available, the parser can only parse .asc files.
multiprocess: bool or int, optional
Indicates whether each file should be processed in a different process.
This can speed up parsing considerably. If not False
, this should be
an int to indicate the number of processes.
asc_encoding: str or None, optional
Indicates the character encoding of the .asc
files, or None
to use
system default.
pupil_size: bool, optional
Indicates whether pupil-size traces should be stored. If enabled, pupil
size is stored as ptrace_[phase]
columns.
gaze_pos: bool, optional
Indicates whether horizontal and vertical gaze-position traces should
be stored. If enabled, gaze position is stored as xtrace_[phase]
and
ytrace_[phase]
columns.
time_trace: bool, optional
Indicates whether timestamp traces should be stored, which indicate the
timestamps of the corresponding pupil and gaze-position traces. If
enabled, timestamps are stored as ptrace_[phase]
columns.
import eyelinkparser as ep
dm = ep.parse(defaulttraceprocessor=ep.defaulttraceprocessor(
blinkreconstruct=True, downsample=True, mode='advanced'))
For a tutorial about using EyeLinkParser, see:
python-eyelinkparser
is licensed under the GNU General Public License
v3.