margalef {abdiv} | R Documentation |

## Margalef's richness index

### Description

Margalef's richness index

### Usage

```
margalef(x)
```

### Arguments

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

### Details

For a vector `x`

of species counts, Margalef's index is

`D = \frac{S -1}{\log N},`

where `S`

is the total number of species
observed and `N`

is the total number of counts.

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

Equivalent to `margalef()`

in `skbio.diversity.alpha`

.

### Value

The value of Margalef's index, `D \geq 0`

. This index is
undefined when the total number of counts is 1 or 0, in which case we
return `NaN`

.

### References

Margalef R. Information theory in ecology. General Systems 3. 1958;36-71.

### Examples

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

[Package

*abdiv*version 0.2.0 Index]