object
, generally obtained from multiple
NMF runs.dispersion(object, ...)
It is defined as: $$\rho = \sum_{i,j=1}^n 4 (C_{ij} - \frac{1}{2})^2 ,$$ where $n$ is the total number of samples.
By construction, $0 \leq \rho \leq 1$ and $\rho = 1$ only for a perfect consensus matrix, where all entries 0 or 1. A perfect consensus matrix is obtained only when all the connectivity matrices are the same, meaning that the algorithm gave the same clusters at each run. See Kim et al. (2007).