EstimationTools (version 4.0.0)

half_norm_key: Half normal key function

Description

This function provides the half normal key function for model fitting in distance sampling.

Usage

half_norm_key(x, sigma)

Value

A numeric value corresponding to a given value of x and sigma.

Arguments

x

vector of perpendicular distances from the transect.

sigma

scale parameter.

Author

Jaime Mosquera Gutiérrez,

Details

This is the half normal key function with parameter sigma. Its expression is given by

\(g(x) = \exp(\frac{-x^2}{2*\sigma^2},\)

for x > 0.

See Also

Other key functions: hazard_rate_key(), uniform_key()

Examples

library(EstimationTools)

#----------------------------------------------------------------------------
# Example: Half normal function
half_norm_key(x=1, sigma=4.1058)
curve(half_norm_key(x, sigma=4.1058), from=0, to=20, ylab='g(x)')

#----------------------------------------------------------------------------