# Abundance Frequency Count of a Community

### Description

Counts the number of species observed the same number of times.

### Usage

1 | ```
AbdFreqCount(Ns, CheckArguments = TRUE)
``` |

### Arguments

`Ns` |
A numeric vector containing species abundances. |

`CheckArguments` |
Logical; if |

### Details

The Abundance Frequency Count (Chao *et al.*, 2015) is the number of species observed each number of times.

It is a way to summarize the species distribution.

### Value

A two-column matrix. The first column contains the number of observations, the second one the number of species observed this number of times.

### Author(s)

Eric Marcon <Eric.Marcon@ecofog.gf>

### References

Chao, A., Hsieh, T. C., Chazdon, R. L., Colwell, R. K., Gotelli, N. J. (2015) Unveiling the Species-Rank Abundance Distribution by Generalizing Good-Turing Sample Coverage Theory. *Ecology* 96(5): 1189-1201.

### See Also

`PhyloEntropy`

, `ChaoPD`

### Examples

1 2 3 4 5 6 7 8 9 10 | ```
# Load Paracou data (number of trees per species in two 1-ha plot of a tropical forest
# and their taxonomy)
data(Paracou618)
# Ns is the vector of abundances of the first plot
Ns <- Paracou618.MC$Nsi[, 1]
# Return the abundance frequency count
(AbdFreqCount(Ns) -> afc)
plot(afc, xlab="Number of observations", ylab="Number of species")
lines(afc)
``` |