Gaze position ============= [GazeFeatures](../../argaze.md/#argaze.GazeFeatures) defines a [GazePosition](../../argaze.md/#argaze.GazeFeatures.GazePosition) class to handle point coordinates with a precision value. ``` python from argaze import GazeFeatures # Define a basic gaze position gaze_position = GazeFeatures.GazePosition((123, 456)) # Define a gaze position with a precision value gaze_position = GazeFeatures.GazePosition((789, 765), precision=10) # Access to gaze position value and precision print(f'position: {gaze_position.value}') print(f'precision: {gaze_position.precision}') ``` ## Validity [GazeFeatures](../../argaze.md/#argaze.GazeFeatures) defines also a [UnvalidGazePosition](../../argaze.md/#argaze.GazeFeatures.UnvalidGazePosition) class that inherits from [GazePosition](../../argaze.md/#argaze.GazeFeatures.GazePosition) to handle case where no gaze position exists because of any specific device reason. ``` python from argaze import GazeFeatures # Define a basic unvalid gaze position gaze_position = GazeFeatures.UnvalidGazePosition() # Define a basic unvalid gaze position with a message value gaze_position = GazeFeatures.UnvalidGazePosition("Something bad happened") # Access to gaze position validity print(f'validity: {gaze_position.valid}') ``` ## Distance [GazePosition](../../argaze.md/#argaze.GazeFeatures.GazePosition) class provides a **distance** method to calculate the distance to another gaze position instance. ![Distance](../../img/distance.png) ``` python # Distance between A and B positions d = gaze_position_A.distance(gaze_position_B) ``` ## Overlapping [GazePosition](../../argaze.md/#argaze.GazeFeatures.GazePosition) class provides an **overlap** method to test if a gaze position overlaps another one considering their precisions. ![Gaze overlapping](../../img/overlapping.png) ``` python # Check that A overlaps B if gaze_position_A.overlap(gaze_position_B): # Do something if A overlaps B ... # Check that A overlaps B and B overlaps A if gaze_position_A.overlap(gaze_position_B, both=True): # Do something if A overlaps B AND B overlaps A ... ``` ## Timestamped gaze positions [TimeStampedGazePositions](../../argaze.md/#argaze.GazeFeatures.TimeStampedGazePositions) inherits from [TimeStampedBuffer](../../argaze.md/#argaze.DataStructures.TimeStampedBuffer) class to handle especially gaze positions. ### Import from dataframe It is possible to load timestamped gaze positions from a [Pandas DataFrame](https://pandas.pydata.org/docs/getting_started/intro_tutorials/01_table_oriented.html#min-tut-01-tableoriented) object. ```python import pandas # Load gaze positions from a CSV file into Panda Dataframe dataframe = pandas.read_csv('gaze_positions.csv', delimiter="\t", low_memory=False) # Convert Panda dataframe into TimestampedGazePositions buffer precising the use of each specific column labels ts_gaze_positions = GazeFeatures.TimeStampedGazePositions.from_dataframe(dataframe, timestamp = 'Recording timestamp [ms]', x = 'Gaze point X [px]', y = 'Gaze point Y [px]') ``` ### Iterator Like [TimeStampedBuffer](../../argaze.md/#argaze.DataStructures.TimeStampedBuffer), [TimeStampedGazePositions](../../argaze.md/#argaze.GazeFeatures.TimeStampedGazePositions) class provides iterator feature: ```python for timestamp, gaze_position in ts_gaze_positions.items(): # Do something with each gaze position ... ```