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I would like to identify single-cell clusters where each sample is evenly represented in it. Is it OK to calculate the Shannon-Weiner index from the sample counting data of each cluster? I am worrying that the entire population of each sample is not balanced, therefore I plan to normalize within-cluster counts with total cell number in each cluster.

My naive idea is summarized in these formulas:

$$ E_{i} = \frac{\sum_{j=1}^{N_{sample\,}}P_{i,j}\log_2{P_{i,j}}}{E_{max}} $$

where,

$$ P_{i,j} = \frac{C_{i,j}}{\sum_{i=1}^{N_{cluster}}} + pseudo\_count $$

$C_{i,j}$ is the count of sample $j$ in cluster $i$.

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  • $\begingroup$ What is the purpose of the pseudocount? $\endgroup$ Jul 12 '21 at 18:54
  • $\begingroup$ Pseudocount aside, you are proposing to estimate a rescaled Shannon entropy onto $[0,1]$ of each cluster. That is fine if that is what you want to know. $\endgroup$ Jul 12 '21 at 18:58
  • $\begingroup$ @Galen Log2P_ij undefined if C_ij equals to zero. That is the cluster does not have any instances of the sample. Are there other approaches to avoid this? $\endgroup$
    – J.G
    Jul 13 '21 at 14:09
  • $\begingroup$ That's quite understandable, however by convention we take the right-limiting value $H(0) \triangleq \lim_{p \rightarrow 0^+} p \log_2(p) = 0$. $\endgroup$ Jul 13 '21 at 14:21

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