Fork me on GitHub"

# skbio.diversity.alpha.simpson

`skbio.diversity.alpha.``simpson`(counts)

  Calculate Simpson’s index.

  State: Experimental as of 0.4.0.

  Simpson’s index is defined as `1 - dominance`:

  \[1 - \sum{p_i^2}\]

  where \(p_i\) is the proportion of the community represented by OTU \(i\).

  Parameters: | counts (1-D array_like, int) – Vector of counts.
  Returns: | Simpson’s index.
  Return type: | double

  See also

  `dominance()`

  Notes

  The implementation here is `1 - dominance` as described in [1]. Other references (such as [2]) define Simpson’s index as `1 / dominance`.

  References

  [1] | http://folk.uio.no/ohammer/past/diversity.html

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