Creates neighbors based on a distance band. By default, creates a distance band with the maximum distance of k-nearest neighbors where k = 1 (the critical threshold) to ensure that there are no regions that are missing neighbors.
The lower threshold of the distance band. It is recommended to keep this as 0.
upper
The upper threshold of the distance band. By default is set to a critical threshold using critical_threshold() ensuring that each region has a minimum of one neighbor.