recapr (version 0.4.3)

powChapman: Power for Hypothesis Testing Using the Chapman Estimator

Description

Approximates the power of a hypothesis test of the Chapman estimator by means of many simulated draws from a specified alternative distribution, conditioned on sample sizes.

Usage

powChapman(
  nullN,
  trueN,
  n1,
  n2,
  alpha = 0.05,
  nsim = 10000,
  alternative = "less"
)

Arguments

nullN

The abundance given by the null hypothesis

trueN

The assumed abundance for the power calculation

n1

Number of individuals captured and marked in the first sample

n2

Number of individuals captured in the second sample

alpha

The alpha level for the test

nsim

Number of simulated values to draw. Defaults to 10000.

alternative

Direction of the alternative hypothesis. Allowed values are "less", "greater", or "2-sided". Defaults to "less".

Value

The approximate power of the specified hypothesis test, for the specified alternative value.

See Also

NChapman, vChapman, seChapman, rChapman, pChapman, ciChapman

Examples

# NOT RUN {
powChapman(nullN=500, trueN=400, n1=100, n2=100, nsim=1000)

Ntotry <- seq(from=250, to=450, by=25)
pows <- sapply(Ntotry, function(x)
  powChapman(nullN=500, trueN=x, n1=100, n2=100, nsim=1000))
plot(Ntotry, pows)
# }