h21: Hazard detection function of form 'h2' with g(0)<1

In david-borchers/LT2D: Line transect estimation in two dimensions

Description

This hazard function has the form k(r,y)=c*[a*√(r^2-y^2)/r^{(b+1)}]; b>2 modified from Hayes and Buckland (1983) p37, where c is imperfect detectability i.e. g(0)<1.

Usage

h21(y, x, b)

Arguments

y	Forward distance
x	perpendicular distance
b	parameter vector, where b[2] is log(theta) and b[3] is qlogis(b[3]) detectability at the observer i.e. g(0)=c

Value

probability of detection given that an animal is availabe at location x,y #'@examples h21(0.5,0.5,b=c(log(c(0.75,1)),qlogis(0.9)))

References

Hayes, R. J., and S. T. Buckland. "Radial-distance models for the line-transect method." Biometrics (1983): 29-42.

david-borchers/LT2D documentation built on Aug. 17, 2020, 1:37 a.m.