Structchord

$D_{Structchord} = \sqrt{ \sum_{j=1}^{S_T} \left ( \frac{S_{Aj}}{\sqrt{\sum_{j=1}^{S_T} S_{Aj}^2 }} - \frac{S_{Bj}}{\sqrt{\sum_{j=1}^{S_T} S_{Bj}^2}} \right )^2 }$
• where $$S_{Aj}$$ is the abundance of sample A in the jth OTU.
• where $$S_{Bj}$$ is the abundance of sample B in the jth OTU.