Coordinate systems in Stytra ============================ Stytra follows the common convention for displaying images on screens: the x axis increases to the right and the y axis increases downward, with (0,0) being the upper right corner. For the recorded coordinates, the same holds. The angles correspondingly increase clockwise. :ref:`calibration` establishes a mapping between the camera and projector coordinate systems. The :attr:`~stytra.calibration.CircleCalibrator.cam_to_proj` and :attr:`~stytra.calibration.CircleCalibrator.proj-to_cam` matrices transform points from one coordinate system to another. Visual stimuli are usually configured to take dimensions in millimeters, whereas the scaling factor is taken from the calibration procedure.