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# Simpson

From mothur

Validate output by making calculations by hand

***.simpson**

These files give the classic Simpson Index of diversity.

<math>H_{Simpson} = \frac {\sum_{i=1}^{S_{obs}} {S_i \left ( S_i - 1 \right )}}{N \left( N-1 \right )}</math>

For the Amazonian dataset, the Simpson Index is 0.0044.

Example calculations below will be performed using data from the 70.fn.shared file with an OTU definition of 0.03.