detection.prob {distance.sample.size} R Documentation

## Calculate detection probabilities.

### Description

Calculates the detection probability at one or more distances.

### Usage

detection.prob(d, detection.function = c("halfnormal", "hazard"), theta,
deriv, stop = F)


### Arguments

 d The distance or distances of interest. detection.function The detection function. Only "halfnormal" and "hazard" (hazard rate) are supported at present. theta The detection function parameters. A single value for halfnormal, or a vector of two values for hazard rate. deriv Optional numeric value specifying whether a derivative is required. If missing, the function returns the detection probabilities at distances d. If deriv is equal to 1 or 2, the derivatives of the detection function with respect to theta[deriv] at d are returned. Note that the halfnormal detection function has only one parameter, so setting deriv=2 and detection.function="halfnormal" will result in an error. stop Set to T to open a browser window (for debugging purposes)

### Value

A vector of detection probabilities corresponding to the distances in d.

### References

Buckland S, Anderson D, Burnham K, Laake J and Borchers D (2001). Introduction to Distance Sampling: Estimating Abundance of Biological Populations. Oxford: Oxford University Press.

Clark, R. G. (2016), "Statistical efficiency in distance sampling," PLoS One, forthcoming, www.plosone.org

### Examples

dvalues <- seq(from=0,to=1,by=0.001)
dprobs <- detection.prob(d=dvalues,detection.function="hazard",theta=c(0.448,2))
plot(dvalues,dprobs,type="l",ylim=c(0,1))


[Package distance.sample.size version 0.0 Index]