MicroSaccadeFeatures

Micro saccades are defined as a subclass of saccades, satisfying certain maximum speed and minimum dispersion conditions.

class eyefeatures.features.stats.MicroSaccadeFeatures(min_dispersion=1.0, max_speed=10.0, features_stats=None, **kwargs)

Bases: StatsTransformer

Micro Saccade Features. The transformer identities saccades, and then selects micro saccades from them using user-defined set of rules.

Parameters:

• min_dispersion (float) – minimum dispersion of fixation.

• max_speed (float) – maximum speed between fixations.

• features_stats (dict[str, list[str]])

Supported Metrics

• length: Amplitude in pixels.

\[\text{Length(Saccade}_i\text{)} = ||\text{Fixation}_{i+1} - \text{Fixation}_{i} ||_{2}\]

• speed: Velocity in pixels/ms.

\[\text{Speed(Saccade}_i\text{)} = \frac{\text{Length(Saccade}_i\text{)}}{\text{Time}_{i+1} - \text{Time}_{i}}\]

• acceleration: Acceleration in pixels/ms².

\[\text{Acceleration(Saccade}_i\text{)} = \frac{1}{2} \frac{\text{Speed(Saccade}_i\text{)} }{\text{Time}_{i+1} - \text{Time}_{i}}\]

• mask: Transition boolean mask.

\[\text{Mask(Saccade}_i\text{)} = \mathbb{I}[\text{Fixation}_{i}\in\text{ some micro saccade}]\]