# Difference between revisions of "Jest"

Example Calculations

*.sharedJest

Estimating the fraction of sequences that belong to shared OTUs.

Just as the Chao1 richness estimator is a function of the number of OTUs observed once or twice in a sample (6), the estimators of the fraction of sequences in shared OTUs is a function of the number of shared OTUs that are observed at least once or twice in the community being analyzed (8, 7). ${S_{Jest}}$ is essentially a form of the equation for $J_{abund}$ that is not corrected for the presence of unsampled OTUs.

$S_{Jest} = \frac{S_{A,B Chao}}{S1_{chao} + S2_{chao} - S_{A,B Chao}}$,

where,

$S_{A,B Chao}$ = estimated number of OTUs shared between A and B using the $S_{A,B Chao}$ estimator.

$S1_{chao}$ = number of OTUs estimated in A using the Chao estimator.

$S2_{chao}$ = number of OTUs estimated in B using the Chao estimator.

At distance 0.03, the $S_{Jest}$ value is 0.705297.