R/plot_df.R

In dill/ltdesigntester: Test Performance of Line Transect Designs

#' Plot a detection function from an object of class "Detectability"
#'
#' Plot the detection function as specified by a \code{DSsim} "Detectability" object.
#' @export
#' @author David L Miller
#' @param df a "Detectability" object
#' @return just a plot
plot_df <- function(df){
  if(df@key.function=="hn"){
    g <- function(x, sigma, b){
      exp(-x^2/(2*sigma^2))
    }
  }else{
    g <- function(x, sigma, b){
      1-exp(-(x/sigma)^(-b))
    }
  }
  xx <- seq(0, df@truncation, len=500)
  plot(xx, g(xx, df@scale.param, df@shape.param), type="l",
       xlab="Distance", ylab="Probability of detection",
       ylim=c(0, 1),
       main="Detection function")
}