fitEcm | R Documentation |
Fits the Equal Capture Model (ECM) to count data to obtain the MLE for population size
fitEcm(data, max.pop)
data |
A two-column data frame with the first column specifiying the capture class (i.e. individuals in class i were caught i times) and the second column specifying the number of individuals in each class |
max.pop |
The maximum population size |
The ECM model fit by this function assumes that all individuals are equally likely to be "captured".
The value is specified for max.pop
is not likely to matter as long as it is much greater than the maximum likelihood estimate for population size.
Note that if the data contains only singletons, the data is not informative and the maximum likelihood estimate for population size will be equal to max.pop
an object of class capfit
containing the follow elements:
The model specified
The likelihood of the model
The maximum likelihood estimate for population size
The mean number of captures per individual
The total number of individuals in the sample
Total number of samples in the data set
The maximum population size specified by max.pop
Matthew W. Pennell
Miller C. R., P. Joyce and L.P. Waits. 2005. A new method for estimating the size of small populations from genetic mark-recapture data. Molecular Ecology 14:1991-2005.
Pennell, M. W., C. R. Stansbury, L. P. Waits and C. R. Miller. 2013. Capwire: a R package for estimating population census size from non-invasive genetic sampling. Molecular Ecology Resources 13:154-157.
simEcm
## Simulate data under Equal Capture Model data <- simEcm(n=40, s=150) ## Fit Equal Capture Model to Data res <- fitEcm(data=data, max.pop=200) res
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