A Python/Drawbot script able to visualize gaze_position.npy by Pupil Capture eye-tracker

gazePosition_visualization.py

################################
# Gaze positions visualization #
################################

### Modules
import numpy
import sys
from operator import itemgetter

### Functions
def drawOvals(points, diameter):
    for point in points:
        x = point[0]
        y = point[1]
        oval(x-diameter/2, y-diameter/2, diameter, diameter)
        
def drawLines(points):
    bezierPath = BezierPath()
    bezierPath.moveTo(points[0])
    
    for each_point in points[1:]:
        bezierPath.lineTo(each_point)
        
    drawPath(bezierPath)
    
def sliceArrayBySeconds(sequence, minimum, maximum):
    sliced_sequence = [x for x in sequence if minimum <= x[1] <= maximum]
    return sliced_sequence


### Variables
input_path = 'gaze_positions.npy'
diameter = 10
minimum_time = 30
maximum_time = 40


### Instructions
# Reading numpy data
data = numpy.load(input_path)

# Converting to float and selecting coordinates
points_coordinates_percentage = []
time_stamps = []
for d in data:
    points_coordinates_percentage.append([float(x) for x in d[:2]])
    time_stamps.append(float(d[4]))

# Adjusting time stamps
lower_time_stamp = min(time_stamps)
for i, each_time_stamp in enumerate(time_stamps):
    time_stamps[i] = each_time_stamp - lower_time_stamp

# Adjusting to monitor dimension
points_coordinate_pixel = []
for each_point in points_coordinates_percentage:
	pixel_point = (each_point[0]*1280, each_point[1]*720)
	points_coordinate_pixel.append(pixel_point)

# Zipping coordinates and timestamps in a dict
points_and_timestamps = dict(zip(points_coordinate_pixel, time_stamps))

# Ordering timeStamps
points_and_timestamps = sorted(points_and_timestamps.items(), key=itemgetter(1), reverse = False)

sliced_points_and_timestamps = sliceArrayBySeconds(points_and_timestamps, minimum_time, maximum_time)

# Canvas dimension
size(1280, 720)

# Graphics qualities
fill(0)
stroke(None)

# drawing dots
coordinates = [x[0] for x in sliced_points_and_timestamps]
drawOvals(coordinates, diameter)

# drawing lines
stroke(0)
fill(None)
drawLines(coordinates)