sExtinct (version 1.1)

Solow1993.eq2: Intermediate level functions to calculate Burgman, Solow1993.eq2, Solow2005.eq7

Description

A collection of functions requiring, in addition to the normal intermediate level inputs of data, alpha and data.out, a test.year value. The test.year (typically set as the current year) is the date that p values of persistance are calculated up to.

Usage

Burgman(sightingdata, alpha, test.year, data.out)
Solow1993.eq2(sightingdata, alpha, test.year, data.out)
Solow2005.eq7(sightingdata, alpha, test.year, data.out)

Arguments

sightingdata

A data.frame with two columns, the first containing the year at which a sighting has (or as not) occured, the second a column of the number of sightings that have occured in each year. Can be gaps in the data (which are filled in by the function as 0 sightings within that year). Column names are not restricted. Data must be ranked from oldest at the top, to most recent at the bottom, and restricted to a single row per year. See example.data.

alpha

A 1-alpha confidence interval is calculated for a given value of alpha, typically set as 0.05 (i.e. a 95%CI).

test.year

A year which chance of persistance is calculated up until, typically set as the current year (i.e. test whether the species is currently predicted to be extant or extinct).

data.out

A TRUE/FALSE argument where TRUE produces the predicted chance of persistance at each time step (where applicable), and FALSE gives a simple output with the predicted date of extinction only.

References

Burgman, M. A., Grimson, R. C., and Ferson, S. (1995). Inferring Threat from Scientific Collections. Conservation Biology, 9(4), 923-928. Solow (1993). Inferring extinction from sighting data. Ecology, 74(3), 962-964. Solow (2005). Inferring extinction from a sighting record. Mathematical Biosciences, 195(1), 47-55.

See Also

Solow1993.eq2.fun

Examples

data(example.data)
Burgman(example.data, alpha=0.05, test.year=2012, data.out=FALSE)