ip0: Inverse power hazard detection function

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

Description

Inverse power hazard function, as per Borchers and Langrock (in press): Has form h(y,x)=theta[1]*(1/sqrt(1+(x)^2+(y)^2))^(theta[2]+1).

Usage

ip0(y, x, b)

Arguments

y	Forward distance
x	perpendicular distance
b	2-parameter vector, where b[1] is log(theta[1]) and b[2] is log(theta[2]).

Value

probability of detection given that an animal is availabe at location x,y

References

Borchers, D.L and Langrock, R."Double-observer line transect surveys with Markov- modulated Poisson process models for animal availability" Biometrics (in press).

Examples

b=c(5.2919208, 8.4701307)
ip0(0.05,0.05,b=b)
yy=seq(0,0.03,length=100);xx=rep(0,100)
hh=ip0(yy,xx,b=b)
plot(yy,hh,type="l")

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