Adding Saccade distance attribute.

1 files changed, 11 insertions, 0 deletions

diff --git a/src/argaze/GazeFeatures.py b/src/argaze/GazeFeatures.py
index e5dfdf0..d829e92 100644
--- a/src/argaze/GazeFeatures.py
+++ b/src/argaze/GazeFeatures.py
@@ -146,10 +146,21 @@ class Fixation(GazeMovement):
 class Saccade(GazeMovement):
     """Define abstract saccade as gaze movement."""
 
+    distance: float = field(init=False)
+    """Inferred distance from first and last positions."""
+
     def __post_init__(self):
 
         super().__post_init__()
 
+        _, start_position = self.positions.first
+        _, end_position = self.positions.last
+
+        distance = numpy.linalg.norm( numpy.array(start_position.value) - numpy.array(end_position.value))
+
+        # Update frozen distance attribute
+        object.__setattr__(self, 'distance', distance)
+
 class UnknownGazeMovement(GazeMovement):
     """Define abstract unknown gaze movement."""