Fisher Alpha
Solve Fisher's log-series diversity parameter from S = alpha × ln(1 + N/alpha). A finite positive solution exists when the observed species count is smaller than the individual count.
Description
Solve Fisher's log-series diversity parameter from S = alpha × ln(1 + N/alpha). A finite positive solution exists when the observed species count is smaller than the individual count.
Fisher Alpha is a focused biology tool that solve Fisher's log-series diversity parameter from S = alpha × ln(1 + N/alpha). A finite positive solution exists when the observed species count is smaller than the individual count. It calculates locally from the values you enter and exposes the result without changing the source observations.1
When to use Fisher Alpha
Use Fisher Alpha when you need to solve Fisher's log-series diversity parameter from S = alpha × ln(1 + N/alpha). A finite positive solution exists when the observed species count is smaller than the individual count. Enter Species count S and Individual count N using the definitions and units below so the result can be reproduced.
- Species count S
- An integer count or setting greater than or equal to 1.
- Individual count N
- An integer count or setting greater than or equal to 1.
How Fisher Alpha calculates the result
The published tool contract uses this rule: Solve Fisher's log-series diversity parameter from S = alpha × ln(1 + N/alpha). A finite positive solution exists when the observed species count is smaller than the individual count.
- Fisher alpha
- The calculated fisher alpha.
Limitations of Fisher Alpha
The calculation does not propagate measurement uncertainty, sampling error, or biological and chemical variability.
Alternative or Complementary measurements
Retain the original Species count S and Individual count N values and their units alongside the result. Log Series Alpha Proxy is useful when you instead need to compute a documented Fisher-lite proxy for the log-series alpha parameter as species count divided by the natural logarithm of total individuals plus one. Brillouin Index provides another view by helping you compute the Brillouin diversity index HB = (ln(N!) - sum(ln(ni!))) / N from three species counts using loop-based log factorials for communities up to 10000 individuals.
References
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Diversity index — Wikipedia contributors
Similar or alternative tools
- Log Series Alpha Proxy
Compute a documented Fisher-lite proxy for the log-series alpha parameter as species count divided by the natural logarithm of total individuals plus one.
- Brillouin Index
Compute the Brillouin diversity index HB = (ln(N!) - sum(ln(ni!))) / N from three species counts using loop-based log factorials for communities up to 10000 individuals.
- Whittaker Beta Diversity
Compute Whittaker beta diversity betaW = gamma / mean alpha richness from two site species counts and their shared count.