Close 10 feet calculation

[abc1110]

The formula used in the function plot_lines_between_nodes to calculate points which are close to 10 feet is dd = np.where(dist < d_thresh * 6 / 10)
Could you explain this calculation?
Because a different formula is used for ten_feet_violations list
ten_feet_violations = len(np.where(dist_condensed < 10 / 6 * d_thresh)[0])

Thank you!