skbio.diversity.alpha.shannon¶

skbio.diversity.alpha.shannon(counts, base=2)[source]¶

Calculate Shannon entropy of counts, default in bits.

State: Experimental as of 0.4.0.

Shannon-Wiener diversity index is defined as:

\[H = -\sum_{i=1}^s\left(p_i\log_2 p_i\right)\]

where \(s\) is the number of OTUs and \(p_i\) is the proportion of the community represented by OTU \(i\).

Parameters:	counts (1-D array_like, int) – Vector of counts. base (scalar, optional) – Logarithm base to use in the calculations.
Returns:	Shannon diversity index H.
Return type:	double

Notes

The implementation here is based on the description given in the SDR-IV online manual [1] except that the default logarithm base used here is 2 instead of \(e\).

References

[1]	http://www.pisces-conservation.com/sdrhelp/index.html