User manual

Data Files

detection configurations into a new .INI file. Copy the original EDF file to the

current EyeLink host directory (“C:\ELCL\EXE” by default). From the DOS

command prompt, type:

elcl -reparse {SOURCE_EDF} {DEST_EDF} -c {configuration_INI_FILE}

where {SOURCE_EDF} is the name of the original EDF file;

{DEST_EDF} is the name of the destination EDF file where the parsed

data should be saved;

{configuration_INI_FILE} the intended configuration file should be used.

The following example illustrates how to reparse the TEST.EDF file with a new

set of parser configurations contained in the PARSER2.INI file and save the

output data to TEST_NEW.EDF.

ELCL -REPARSE TEST TEST_NEW -C PARSER2.INI

4.4 File Data Types

The data contents of an EDF file are organized in two streams: samples and

events. Samples are used to record instantaneous eye position data, while

events are used to record important occurrences, either from the experimental

application or from changes in the eye data.

Both samples and events can report eye data in several forms. These are

discussed in the description of sample data. Eye movement data is parsed by

the EyeLink 1000 tracker on-line and used to generate eye-movement events,

which are discussed with application messages and button events.

4.4.1 Samples

Samples are records of eye-position, pupil size, and button or input states. The

EyeLink 1000 tracker can record up to 2000 samples per second in a

monocular tracking mode or up to 1000 samples per second in a binocular

tracking mode depending on your system configuration and tracker licensing.

Each sample is stored as a binary record in the EDF file, with simple

compression used to minimize disk space. Even with compression, recording

1000 samples per second will create very large EDF files: about 15K of data per

second.