The basic algorithm is quite simple, but there are some parameters and some additional heuristics that may be tuned or turned off if desired.  See parseinputs.m for a complete list of command line parameters.  

The basic data flow is as follows:
-Look for missing data and blinks
-Low-pass filter and take instantaneous velocity.  
-Low-pass filter and in a sliding window calculate the ratio of the eigenvalues of the x-y eye data.  
-Use a combination of local velocity and ratio of principle axis to determine smooth pursuit, fixation or saccade
-combine pro-saccades into single saccades (optional)
-apply several heuristics such as remove saccades less than xxx degrees and remark events with too short of time based on the events that came before and after.
-display eye trace and summary plots (optional)

Please see the readme.txt in the main source folder.

The latest source is available for download using SVN.  Please e-mail David J Berg to request access to the source tree.  The software is published under the GNU public licence.  

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.