# Spearman

$D_{Spearman} = 1 - \frac{6 \sum_{j=1}^{S_T} \left ( rank(S_{Aj}) - rank(S_{Bj}) \right )^2} {S_T (S^2_T-1)}$
• where $$rank(S_{Aj})$$ is the number of OTUs in sample A with higher or equal abundance to $$S_{Aj}$$.
• where $$rank(S_{Bj})$$ is the number of OTUs in sample B with higher or equal abundance to $$S_{Bj}$$.
• where S_T is the total number of OTUs.