int.chao {fossil} | R Documentation |
Internal function for chao estimators
Description
Computes the Chao species estimator for both chao1
and chao2
estimators
Usage
int.chao(x)
Arguments
x |
a vector of positive integers or zero of any length |
Details
This function is typically only called internally by the functions chao1
and chao2
. The function has a built in bias correction, such that it
will not return values of infinity or non-numbers.
Value
Estimated numer of species using the Chao estimator.
Author(s)
Matthew Vavrek
References
Chao, A. 1984. Nonparametric estimation of the number of classes in a population. Scandinavian Journal of Statistics 11: 265-270.
See Also
For the more useful implementations of the Chao estimator, see chao1
for the abundance based estimator or chao2
for the incidence based estimator
Examples
## create example data set
a<-c(4,5,1,1,2,0,0,1,3,0,8,45,23)
int.chao(a)
## a data set which would give NaN using classic (ie not bias corrected) version
a<-c(4,5,0,0,2,0,0,0,3,0,8,45,23)
int.chao(a)
[Package fossil version 0.4.0 Index]