Statistics of the synthetic data and the corresponding vortex detection results by ASDA. Green and yellow dots in panel a are the locations of generated and detected vortices, respectively. Panel b: close-up view of the black box in panel a. Green arrows represent the velocity field. Blue (red) dots and curves are the centres and edges of vortices with anticlockwise (clockwise) rotations. Panels c and d: distributions of the radii and rotating speeds of the generated (green) and detected (yellow) vortices.