Spectral clustering, DBScan, HDBScan - Bug

Spectral clustering

Fails with sparse graphs

Warning:

UserWarning: Graph is not fully connected, spectral embedding may not work as expected. warnings.warn("Graph is not fully connected, spectral embedding"

Error raised:

AttributeError: 'SpectralClustering' object has no attribute 'predict'

Tested datasets

Error: Chili's Hyd, Telecom Customer Services (no warning raised about graph sparsity).

Success: Crime against women, Telecom subscribers

DBScan, HDBScan

Reproduced this (no attribute 'predict') bug with DBScan and HDBScan algorithms. Tested for Chili's Hyd dataset.