calculate.theta.given.mean.detection.prob {distance.sample.size} | R Documentation |
Calculates the value of the first element of the detection parameters theta based on a supplied value of the average detection rate. Primarily for internal use.
calculate.theta.given.mean.detection.prob(detection.function, theta2, w,
mean.detection.prob.value, stop = F)
detection.function |
The detection function. Only "halfnormal" and "hazard" (hazard rate) are supported at present. |
theta2 |
The second detection parameter for the hazard rate model (the shape parameter). Not required for halfnormal. |
w |
The maximum range of observation. Objects at distance greater than w from the observer are assumed to never be recorded. |
mean.detection.prob.value |
The mean detection probability over the range of observation. |
stop |
Set to T to open a browser window (for debugging purposes) |
The value of the first parameter of theta.
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
calculate.theta.given.mean.detection.prob(detection.function="hazard",theta2=2,w=1,
mean.detection.prob.value=0.6) # should equal 0.448
calculate.theta.given.mean.detection.prob(detection.function="halfnormal",w=1,
mean.detection.prob.value=0.6) # should equal 0.502