mcintosh_e {abdiv} | R Documentation |

## McIntosh's evenness measure E

### Description

McIntosh's evenness measure E

### Usage

```
mcintosh_e(x)
```

### Arguments

`x` |
A numeric vector of species counts. |

### Details

For a vector `x`

of raw species counts, the McIntosh evenness measure
is

`E = \frac{\sqrt{\sum_i x_i^2}}{\sqrt{(N - S + 1)^2 + S - 1},}`

where `N`

is the total number of counts and `S`

is the total
number of species observed.

This index is appropriate only for raw counts, not transformed counts or proportions.

Equivalent to `mcintosh_e()`

in `skbio.diversity.alpha`

.

### Value

McIntosh's evenness measure, `0 < E \leq 1`

. The index is
undefined when the total number of counts is 0, in which case we return
`NaN`

.

### References

Heip C, Engels P. Comparing Species Diversity and Evenness Indices. J. Mar. Bioi. Ass. U.K. 1974;54:559-563.

### Examples

```
x <- c(15, 6, 4, 0, 3, 0)
mcintosh_e(x)
```

[Package

*abdiv*version 0.2.0 Index]