TwoPassDepl: Two Pass Depletion Abundance Estimator
In KevinSee/SiteAbundances: Template

Description Usage Arguments Value Author(s) References Examples

a function to estimate abundance based on a two pass depletion method

1	TwoPassDepl(data, rmInvalid=FALSE, p.threshold=0.2)

`data`	dataframe with two columns containing the counts from each pass
`rmInvalid`	if TRUE, make any abundances NA where the probability of capture is estimated to be below p.threshold
`p.threshold`	the user-defined cutoff for declaring an estimate invalid. Set to 0.2 as a default

`N.hat`	- estimate of abundance
`N.hat.SE`	- standard error of the estimate of abundance
`p.hat`	- estimate of the probability of capture

Kevin See, QCI, Seattle, WA

Lockwood, Roger N. and J. C. Schneider. 2000. Stream fish population estimates by markand-recapture and depletion methods. Chapter 7 in Schneider, James C. (ed.) 2000. Manual of fisheries survey methods II: with periodic updates. Michigan Department of Natural Resources, Fisheries Special Report 25, Ann Arbor.

data(depl.data)
# pull out examples with two-pass depletion data
two.pass.data = subset(depl.data, n.pass==2, select=c('pass.1', 'pass.2'))
# estimate abundance
TwoPassDepl(two.pass.data)