My question has two parts:
1- What clustering algorithms we can use to cluster offline sensor dataset (a dataset of millions of sensors readings that consist of temporal, spatial, and sensed values attributes, ex. Intel Berkeley dataset 2004). Traditional clustering algorithms can not work (except k-means) with such big dataset, and it is difficult to discover the best value for K. Are stream clustering algorithms useful here, but also, how to discover K?
2- As we have different sets of attributes: temporal (date, time of reading), spatial (sensor position in X,Y), and sensed values (temperature, humidity...), we pass all these to a clustering algorithm, or we cluster based on the sensed values only?