### We will be offering mothur and R workshops throughout 2019. Learn more.

# Spearman

From mothur

<math>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)}</math>

- where <math>rank(S_{Aj})</math> is the number of OTUs in sample A with higher or equal abundance to <math>S_{Aj}</math>.
- where <math>rank(S_{Bj})</math> is the number of OTUs in sample B with higher or equal abundance to <math>S_{Bj}</math>.
- where S_T is the total number of OTUs.